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Introduction/Objective. Comparing two materials under the same conditions is the best way to define differences between them. Ceramic-reinforced polyether-etherketone (PEEK) is a polymer that has many possible uses in dentistry as already well-known lithium disilicate ceramics. The aim of this study was to compare peri-implant soft tissue healing and evaluate patient satisfaction with esthetics in different observation periods, as well as the success and survival rate of both types of crowns. Methods. The study was conducted as a clinical, prospective, randomized split-mouth study on 17 patients with bilaterally missing upper teeth of the same type, replaced with dental implants. Study outcomes have been analyzed with subjective (visual analogue scale – VAS scale) and objective parameters (modified bleeding index – MBI, modified plaque index – MPI and peri-implant probing depth – PPD) baseline, six and twelve months after fixing crowns onto the implants. Results. Comparison of the results between PEEK and lithium disilicate crowns showed no statistical differences in terms of MPI, MBI, and PPD in the observed periods. Analyzing MPI during observation periods in the PEEK group of crowns, statistical significance was registered between baseline values and after six months. Also, statistical significance was noticed in terms of PPD during the observation time both in the study and control group of crowns. Results for VAS for the esthetics showed no statistically significant difference between the groups, while VAS for restoration satisfaction showed a statistically significant difference. Conclusion. This study showed that scores of the applied subjective and objective parameters can be a reliable tool to rate the clinical outcome of implant-retained single crowns over time.

Introduction/Objective. Factors such as nature of psychiatric disorder, length of hospitalization and oralside effects of psychotropic medications may considerably contribute to high prevalence of oral diseases among people with schizophrenia, and a consequent need for prosthetic rehabilitation. The aim of this study was to ascertain the oral health level of prosthetic rehabilitated patients with schizophrenia and to consider their needs for future improvement of prosthetic rehabilitation. Methods. The study group comprised 52 patients with schizophrenia, hospitalized at the Dr Laza Lazarević Clinic for Mental Disorders, Belgrade. The control group comprised 52 patients with no psychiatric medical history, treated at the School of Dental Medicine, University of Belgrade. The oral health indices (Decayed, Missing and Filled Teeth Index – DMFT, Community Periodontal Index of Treatment Needs – CPITN, and the Simplified Oral Hygiene Index – OHI-S), socio-demographic characteristics, smoking habits, oral hygiene habits, and previous dental visits were registered in both groups, as well as medical characteristics of the primary disease in the study group patients. Results. Fifty percent of the study group patients had partial mobile dentures, while almost 30% had fixed dentures, in contrast to the control group patients, who prevalently had fixed dentures. In both groups of patients, a statistical significance was observed between partial mobile and fixed dentures wearers, in terms of DMFT index, carious teeth, CPI modified, and OHI-S. Similarly, a statistically significant difference between the groups was observed concerning fixed dentures in terms of carious teeth, filled teeth, CPI modified, and OHI-S. Conclusion. Multidisciplinary approach is needed for complete oral and prosthetic rehabilitation of this group of psychiatric patients.

Background/Aim. In colon and rectal cancer surgery, resection is considered radical when circumferential, proximal and distal resection margins are without the presence of tumor cells. Concept of total mesorectal excision in rectal surgery involves complete removal of the tumor with mesorectal fascia which surrounds lymph nodes, lymphatics and blood vessels. The aim of this study was to determine whether laparoscopic approach provides all parameters of oncological radicality as open surgery of colorectal cancer. Methods. The study included 122 patients with carcinoma of colon and rectum, divided into two equal groups: patients operated on by laparoscopic and those operated on by open approach. In colon surgery we analyzed proximal and distal resection margins, and the number of removed lymph nodes, and in rectal surgery: proximal, distal and circumferential resection margins, and the number of removed lymph nodes. Results. Both groups were comparable in age, sex, American Society of Anesthesiologists (ASA) score, tumor localization, tumor size, and type of surgical operation performed. According to localization of the tumor, the most commonly performed operation was anterior resection of the rectum (60.7% vs. 59%). There was no case of the tumor involvement of the distal margin. Average proximal distance from the tumor on the fixed specimen was 100 vs. 120 mm with statistical significance (p < 0.001). Distal margins were not significantly different, 40 mm in both groups (p = 0.143). In two cases we had circumferential resection margin (CRM) of 1 mm (7.7%) in the laparoscopic group, and in three cases operated conventionally CRM was 1 mm (8.8%). The average number of removed lymph nodes was 15 vs. 16, respectively. Length of hospital stay for patients assigned to the laparoscopic surgery was significantly shorter than for patients operated on by the open approach. Concerning postoperative complications, no significant difference was found between groups. The overall postoperative morbidity was 18% vs. 21.3%, respectively. Conclusion. With laparoscopic approach it is possible to provide all parameters of oncological radicality similarly to the open surgery of colorectal cancer.

Corrective defectological or special educational work is one of the important approaches in the education and rehabilitation of children with disabilities and developmental disorders, regardless of whether these children are educated in special or general conditions. Corrective work, additional support, compulsory extracurricular individual activities or corrective stimulating exercises - are all kinds of individual special educational work based on the specific educational needs and abilities of each individual child. The benefits and values of applying individual special educational work in special education and rehabilitation are numerous; the focus on one student/user, as given by the very nature of this type of teaching or work, is not only a simple spatial orientation of a higher degree but also a new type of relationship, communication and interaction that creates a new quality and development in the discovery and perception of the world around these students/users. Individual special educational work, as an approach, exists in the part of the education system that is intended for the education of students with disabilities, in the so-called special schools for more than 15 years, and it is almost neglected the existing possibility of its application in the entire educational system, in all educational institutions where children and students with disabilities and developmental difficulties learn in an inclusive context. Inclusive education in Serbia, which still faces numerous challenges, should use all available resources in an adequate way. Corrective defectological or special educational work is an insufficiently used inclusive resource in our environment and our educational system.

TiO2 nanopowders were produced by sol-gel technique using TiCl4 as a starting material. For the preparation of crystalline anatase with developed surface area, this aqueous solution has been mixed with 0.05 M or 0.07 M (NH4)2SO4 solution in a temperature-controlled bath. The pH values of the suspension were 7, 8 or 9. According to the x-ray diffraction (XRD) analysis the anatase crystallite sizes were about 12 nm, which coincided with the average particle size revealed by scanning electron microscopy (SEM). The Raman scattering measurements have shown the presence of a small amount of highly disordered brookite phase in addition to dominant anatase phase with similar nanostructure in all synthesized powders. BET measurements revealed that all synthesized catalysts were fully mesoporous, except the sample synthesized with 0.07 M (NH4)2SO4 at pH=9, which had small amount of micropores. The photocatalytic degradation of herbicide Clomazone was carried out for both the pure active substance and as the commercial product (GAMIT 4-EC) under UV irradiation. The best photocatalytic efficiency was obtained for the catalyst with the largest specific surface area, confirming this parameter as crucial for enhanced photocatalytic degradation of the pure active substance and commercial product of herbicide Clomazone. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III45018]

The present study estimated the cracking phenomenon in as-plasma-sprayed hydroxylapatite coatings (HACs) after they were being subjected to the severe cutting conditions in the direction perpendicular to the coating/substrate interface. In order to evaluate the effects of substrate preheating on the occurrence of micro-cracks, the HACs were deposited at different initial substrate temperatures (TS = 20, 100 and 200°C). The changes in phase composition and HA splat morphology with TS were observed and were correlated with the cracking occurrence. The results showed that severe cutting conditions introduced a localized cracking in the regions of HACs dominantly attributed to the brittle hydroxyl-deficient amorphous calcium phosphate (ACP) phase. This effect was particularly observable in the HACs deposited without preheating of substrate. On the other hand, the preheating of substrate reduced the presence of micro-cracks and caused insignificant changes in the average local phase composition. In HACs deposited with preheating of substrate, the HA splats (of which HACs are composed) were thinner and recrystallized HA regions seemed smaller in size and more evenly distributed. These results implied potentially important roles of the HA splat formation mechanism on the distribution of ACP and recrystallized HA regions in the as-plasma-sprayed HACs and the cracking resistance of HACs. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 34022]

This paper deals with importance and position of upbringing of children with disabilities, and it gives a review of ten efficient, evidence-based, support programs created for parents of children with disabilities, which are used globally. Contemporary concept of children upbringing in general includes interaction between parents and children in a process of upbringing and participation of a child in its own development. In this regard, parents of children with disabilities need strong support targeted at strengthening their parental capacities and building special skills, considering their children's disabilities. There are no support programs for parents of children with disabilities in Serbia. Evidence-based and proven support programs for families and parents have to be provided, promoted and offered as constantly available support for parents and children with disabilities within the comprehensive and complex process of upbringing.

Background/Aim. During drilling implant sites, mechanical energy is converted into thermal one resulting in transient rise in temperature of surrounding bone. The temperature of 47°C exeeding one minute impairs osseointegration, compromises mechanical properties of the local bone and could cause early implant failure. This in vitro study aimed to assess the effect of surgical drill guide and temperature of irrigans on thermal changes of the local bone during drilling implant sites, and to test the influence of irrigans temperature on the temperature of surgical drill guide. Methods. A total of 48 specimens obtained from bovine ribs were randomly allocated to four experimental conditions according to the 2 x 2 factorial design: drill guide (with or without) and saline (at 25°C or 5°C). Real-time infrared thermography was used as a method for temperature measurement. The primary outcome was bone temperature change during drilling implant sites measured at 3 osteotomy depths, whereas the second one was change in the temperature of the drill guide. Data were analyzed by Brunner and Langer nonparametric analysis and Wilcoxon test. Results. The effect of drill guide on the changes of bone temperature was significant at the entrance of osteotomy, whereas the effect of saline temperature was significant at all osteotomy levels (p < 0.001). No significant interaction was found (p > 0.05). Guided surgery and irrigation with saline at 25°C were associated with the highest bone temperature increase. Increase in drill guide temperature was significantly higher when saline at 25°C was used (p < 0.001). Conclusion. Guided implant site preparation generates higher temperature of the local bone than conventional drilling, not exceeding the threshold for thermal bone necrosis. Although saline at room temperature provides sufficient heat control during drilling, cooled saline is more effective regardless the use of surgical drill guide.

The titanium dioxide (TiO2) nanopowders were produced by sol-gel technique from tetrabutyl titanate as a precursor by varying some parameters of the sol-gel synthesis like the temperature (500 and 550 °C) and the duration of the calcination (1.5, 2, and 2.5 h). X-ray powder diffraction (XRPD) results have shown that all synthesized nanopowders are dominantly in anatase phase, with the presence of a small amount of rutile in samples calcined at 550 °C. According to the results obtained by Williamson-Hall method, the anatase crystallite size was increased with the duration of the calcination (from 24 to 29 nm in samples calcined at lower, and from 30 to 35 nm in samples calcined at higher temperature). The analysis of the shift and linewidth of the most intensive anatase Eg Raman mode confirmed the XRPD results. The analysis of pore structure from nitrogen sorption experimental data described all samples as mesoporous, with mean pore diameters in the range of 5-8 nm. Nanopowder properties have been related to the photocatalytic activity, tested in degradation of the textile dye (C.I. Reactive Orange 16), carbofuran and phenol. [Projekat Ministarstva nauke Republike Srbije, br. III45018 i br. ON171032]

The titanium dioxide (TiO2) nanopowders were produced by sol-gel technique from tetrabutyl titanate as a precursor, varying the temperature оf calcination (from 500 to 550°C with the step of 10 °C). XRPD results have shown that all synthesized nanopowders are dominantly in anatase phase. The analysis of the shift and linewidth of the most intensive anatase Eg Raman mode confirmed the XRPD results and added the presence of small amount of highly disordered brookite phase in all samples. The analysis of pore structure from nitrogen sorption experimental data described all samples as mesoporous, with mean pore diameters in the range of 1.5 and 4.5 nm. Nanopowder properties have been related to the photocatalytic activity, tested in degradation of the textile dye (C.I. Reactive Orange 16). The sample calcined at temperature of 510°C showed the best photocatalytic performance. [Projekat Ministarstva nauke Republike Srbije, br. III45018 i br. OI171032]

Introduction. Esophageal fibrovascular polyps are rare, benign, intraluminal, submucosal tumor-like lesions, characterized by pedunculated masses which can demonstrate enormous growth. The most frequent symptoms are dysphagia, vomiting and weight loss. Fibrovascular polyps with long stalks can regurgitate into the airways and cause asphyxia. Esophageal inflammatory pseudotumor is extremely rare lesion accompanied with various systemic manifestations as fever, anemia and thrombocytosis. Case report. We presented a 29-year-old man complaining of a long-lasting fever and dysphagia. He was found to have huge pedunculated submucosal tumor of esophagus, surgically completely resected. Histopathological examination showed that this giant tumor, 24 x 9 x 6 cm, was a fibrovascular polyp. The postoperative course was uneventful. The preoperative fever, anemia and thrombocytosis disappeared and did not recur in the postoperative course. Conclusion. We reported a patient with giant esophageal pedunculated tumor with clinical manifestations of inflammatory pseudotumor and histopathological picture of fibrovascular polyp, that we have not found described in the literature before.

Background/Aim. Different types of dental restorations are used for the therapy of unilateral free-end saddle edentulism. Unilateral complex partial denture is one of the indications for the Kennedy class II partial edentulism. The abscence of major connector and denture plate is an advantage compared to the conventional restorations, because of better comfort and shorter period of adaptation. The aim of the study was to analyse the influence of free-end saddle length change on the behaviour of unilateral complex partial denture supporting structures. Methods. Stress levels of the canine and the first premolar as retentional teeth and the attachments were tested under the influence of physiological forces with the loading point shifting distally in relation to the saddle length change. A virtual real size 3D model of the fixed part of the restoration (the canine and the first premolar with milled crowns) was created using the CATIA computer program. It was connected to the mobile part of partial denture with the SD snap in latch attachment. Mobile part of the restoration was designed in the region of 2, 3 and 4 lateral teeth (second premolar, first, second and third molar). By using the finite element method (FEM) stress levels analysis was performed under the load of physiological forces of 150 N in the free-end saddle teeth zone. Results. The results of analysis show that physiological forces cause a different stress distribution on the abutment teeth and the attachment, depending on the saddle length. Conclusion. The stress level values obtained for the abutment teeth as well as the attachment are far lower than the marginal ones. The behaviour of the system changes under this defined stress, but no plastic deformation occurs.

Bacground/Aim. Retentive force of removable partial denture (RPD) directly depends on elastic force of stretched retentive clasp arms (RCAs). During deflection RCA must have even stress distribution. Safety factor is the concept which can be applied in estimating durability and functionality of RCAs. This study was based on analyzing properties of clasps designed by conventional clasp wax profiles and defining the optimal shapes of RCAs for stress distribution and safety factor aspects. Methods. Computer-aided-design (CAD) models of RCAs with simulated properties of materials used for fabrication of RPD cobalt-chromium-molybdenum (CoCrMo) alloy, commercially pure titanium (CPTi) and polyacetale were analyzed. Results. The research showed that geometrics of Rapidflex profiles from the BIOS concept are defined for designing and modeling RCAs from CoCrMo alloys. I-Bar and Bonihard clasps made from CPTi might have the same design as Co- CrMo clasp only by safety factor aspect, but it is obvious that CPTi are much more flexible, so their shape must be more massive. Polyacetale clasps should not be fabricated by BIOS concept for CoCrMo alloy. A proof for that is the low value of safety factor. Conclusion. The BIOS concept should be used only for RCAs made of CoCrMo alloy and different wax profiles should be used for fabricating clasps of other investigated materials. The contribution of this study may be the improvement of present systems for defining the clasps shapes made from CoCrMo alloys. The more significant application is possibility of creating new concepts in defining shapes of RCA made from CPTi and polyacetale.

Forsterite single crystals were grown by the Czochralski technique in air. The lattice parameters were determined by X-ray power diffraction. The IR and Raman spectra of pure and doped (V3+, V5+, and Ni4+) Mg2SiO4 single crystals were measured at room temperature. We studied the phonon properties and discussed the influence of dopants.

Raman spectroscopy has been used for characterization of commercial nanosized TiO2 powder with declared grain size of 5 nm. The Raman spectra measured in Stokes and anti-Stokes regime confirm the anatase phase of TiO2 powder in temperature range 25-1173K. It is shown that phonon-confinement (due to small grain size) and nonstoichiometry (caused by laser irradiation in vacuum) have a great influence on blueshift and broadening of the main Eg Raman mode at low temperatures, while the influence of the strong anharmonic effect becomes dominant at higher temperatures. The phonon confinement effect decreases due to the crystallite growth at temperatures above 673K.

Defect structures related to the intrinsic and extrinsic oxygen vacancies in Ce0.85Nd(Gd)0.15O2-δ nanocrystals were studied by Raman scattering spectroscopy during the temperature treatment. It was observed that the agglomeration effect has major contribution to the stoichiometry of Ce0.85Nd(Gd)0.15O2-δ, namely the change of surface to volume ratio in nanocrystals has significant influence on the concentration and type of defect formed structures. Investigation of these structures is very important from the aspect of application of doped cerium dioxide as an electrolyte in solid oxide fuel cells.

A series of Ce1-xBaxO2-y (5£x£0.20) nanometric powders were synthesized by selfpropagating room temperature synthesis. XRD and Raman scattering measurements were used to characterize the samples at room temperature. All the samples are solid solutions with fluorite type structure with an average crystallite size about 5 nm. The redshift and asymmetric broadening of the Raman F2g mode can be well explained with combined confinement and strain effects because of the nanocrystalline powders nature. The appearance of the additional peaks at ~ 560 cm-1 and ~ 600 cm-1, are attributed to extrinsic and intrinsic O2- vacancies in ceria lattice. Raman spectra of temperature treated Ce0.80Ba0.20O2-d sample revealed the instability of this system.

Mechanical activation was used as a method for modification of the structural and optical properties of commercial ZnO powder. For this purpose zinc oxide powder was mechanically treated by grinding in a high-energy vibro-mill in a continual regime in air up to 300 minutes. Starting and modified ZnO samples were characterized using XRD, BET and TEM measurements. Optical properties of these samples were investigated by Raman and photoluminescence (PL) spectroscopy. The color of commercial ZnO powder was white while mechanically activated ZnO powder was dark yellow, indicating the presence of nonstoichiometry. In the Raman spectra of non-activated sample Raman modes of bulk ZnO were observed, while the spectra of modified samples point out structural and stoichiometric changes. The PL spectra of modified samples excited by 325 and 442 nm lines of a He-Cd laser show great difference with respect to the spectra of the original sample. This study confirms that change in the defect structure of the ZnO crystal lattice introduced by mechanical activation affects the optical properties of this material.

The infrared (IR) reflectivity of laser synthesized TiO2 nanopowder in the anatase phase with a small deviation from stoichiometry is reported. The samples were characterized by SEM, XRD and BET measurements as well as Raman and photoluminescence spectroscopy. Analysis of the far IR reflectivity spectrum of the nanopowder reveals a presence of a plasmon mode. The charge carriers resulting from the lattice defects, mainly oxygen vacancies, are responsible for this mode. The dielectric function in a factorized form with a plasmon contribution is used to model the IR reflectivity spectrum and a good agreement between theoretical and experimental results has been found.

Evolution as in all segments of human behavior and existence has left traces on human teeth. The aim of this study was to determine the frequency of the supernumerary teeth in skeletal remains found at the archeological site Stara Torina and SEM evaluation of the changes on the supernumerary teeth. The study included 90 skulls and 81 jaws of both sexes with average age 20-60 years. Supernumerary teeth were prepared for SEM for analyzing dental tissues. Six supernumerary teeth were found, among them five mesiodensand one paramolar. The frequency of hyperdontia in these skeletal remains is 2,1%. Mesiodens is different morphologically from the incisor it replaced and took part in occlusal contacts during mastication. Paramolar is different morphologically from molar teeth and it did not take part in occlusal contacts during mastication because of its low adherence for bone tissues and small dimensions.

Abstract Background Due to the complexity of health system reform in the post-conflict, post-disaster, and development settings, attempts to restructure health services are fraught with pitfalls that are often unanticipated because of inadequate preliminary assessments. Our proposed Integrated Multimodal Assessment – combining quantitative and qualitative methodologies – may provide a more robust mechanism for identifying programmatic priorities and critical barriers for appropriate and sustainable health system interventions. The purpose of this study is to describe this novel multimodal assessment using emergency medicine in post-conflict Serbia as a model. Methods Integrated quantitative and qualitative methodologies – system characterization and observation, focus group discussions, free-response questionnaires, and by-person factor analysis – were used to identify needs, problems, and potential barriers to the development of emergency medicine in Serbia. Participants included emergency and pre-hospital personnel from all emergency medical institutions in Belgrade. Results Demographic data indicate a loosely ordered network of part-time emergency departments supported by 24-hour pre-hospital services and an academic emergency center. Focus groups and questionnaires reveal significant impediments to delivery of care and suggest development priorities. By-person factor analysis subsequently divides respondents into distinctive attitudinal types, compares participant opinions, and identifies programmatic priorities. Conclusions By combining quantitative and qualitative methodologies, our Integrated Multimodal Assessment identified critical needs and barriers to emergency medicine development in Serbia and may serve as a model for future health system assessments in post-conflict, post-disaster, and development settings.