Search

Adhesion in restorative dentistry represents a relation between dental materials and hard dental tissues which may be affected by many factors such as tooth characteristics etc. Adhesive systems in dentistry are materials which allow intimate connection of two different surfaces. Experiments in dental adhesion began in 1950s in England when dr Oscar Hagger developed a first chemically polymerized monomer. His work influenced further development of dental adhesives. In 1955 a breakthrough happened when dr Buonocore suggested enamel acid etching technique using 85% phosphoric acid for 30 seconds. Research that followed decreased acid concentration to 50% and later to contemporary 32-37%. Researches have continued investigations on adhesive systems and adhesive procedure improvements and their work led to current seventh generation of adhesive systems. There are many classifications of adhesive systems which were suggested during their development. The latest classification which is accepted in the literature suggests two groups according to the adhesive approach: total etch adhesive systems using acid etching technique and selfetching adhesive systems. Total etch adhesive systems represent systems which may be used in two or three steps or phases. Enamel and dentin etching with 30-40% ortophosphoric acid is the first step in application of these materials regardless of the number of application phases of these systems. Selfetching adhesive systems do not require acid etching as a separate step because they prime and condition enamel and dentine at the same time. This effect is achieved by their possibility to incorporate smear layer and partially dissolve hydroxyapatite which leads to resin infiltrated zone with minerals. Universal adhesive systems are the latest improvement since they may be used with or without acid etching step. Either way, all the advantages and good bond strength on dentin are kept. These adhesives are selfetching but have an ability to adjust to different clinical situations. The decision on adhesion procedure of these systems is left to the operator depending on their experience and wish in relation on the case. Difference in hard dental tissues composition of deciduous and permanent dentition suggests a possible difference in adhesive systems application. In order to determine significant differences in materials and their interaction with different types of dentition clinical and laboratory investigations are conducted..., Adhezija u restaurativnoj stomatologiji predstavlja vezu između materijala za ispune i tvrdih zubnih tkiva. Adhezivna sredstva u stomatologiji su materijali koji omogućavaju da se dve površine intimno spoje. Eksperimenti u vezi vezivanja smole za gleđ i dentin su počeli 1950. godine u Engleskoj kada je dr Oskar Hagger razvio hemijski polimerizujući monomer a njegov rad je uticao na razvoj ranih adhezivnih sistema. Važnije istraživanje se dogodilo 1955. godine kada je uvedena tehnika nagrizanja kiselinom od strane dr Buonocore-a, koji je predložio tretiranje gleđi 85% fosfornom kiselinom u trajanju od 30 sekundi. Istraživanja koja su usledila narednih godina, dovela su do toga da se koncentracija fosforne kiseline umanjila prvobitno na 50% a kasnije i na sadašnjih 32-37%. Postoje mnoge podele i klasifikacije adhezivnih sistema koje su nastale tokom njihovog razvoja. Klasifikacija novijeg datuma, prihvaćena u literaturi, deli savremene adhezivne sisteme u dve grupe u zavisnosti od pristupa prema kom se koriste: adhezivni sistemi sa nagrizanjem gleđi i dentina ortofosfornom kiselinom i samonagrizajući adhezivni sistemi. Adhezivni sistemi sa nagrizanjem gleđi i dentina ortofosfornom kiselinom predstavljaju sisteme sa potpunim nagrizanjem čvrstih zubnih tkiva koji se primenjuju u tri ili dve faze. Nagrizanje gleđi i dentina ortofosfornom kiselinom koncentracije 30-40%, predstavlja prvu fazu primene ovih adhezivnih sistema bez obzira da li su u pitanju dvofazna ili trofazna sredstva. Samonagrizajući adhezivni sistemi ne zahtevaju nagrizanje ortofosfornom kiselinom kao zaseban korak tokom primene jer istovremeno nagrizaju i pripremaju gleđ i dentin. Ovakav efekat postižu zahvaljujući svojoj mogućnosti da prodiru kroz razmazni sloj i delimično rastvaraju hidroksiapatit, pri čemu se stvara zona infiltrirana smolom u kojoj se nalaze minerali. Univerzalni adhezivni sistemi predstavljaju novinu jer se mogu koristiti sa potpunim nagrizanjem gleđi i dentina ili kao samonagrizajući bez kompromitovanja dobrih osobina i jačine veze na dentinu. Pomenuti adhezivi su u stvari samonagrizajući sa mogućnošću prilagođavanja različitim kliničkim situacijama. Odluka o načinu primene ovih adhezivnih sistema se zasniva na proceni samog stomatologa u odgovarajućoj kliničkoj situaciji. Razlika u građi tvrdih zubnih tkiva mlečne i stalne denticije ukazuje da možda postoji razlika ne samo u primeni restaurativnih stomatoloških materijala već i u njihovom načinu primene. Kako bi se utvrdile značajne razlike u samim materijalima za ispune i njihovim osobinama vezanim za različite vrste denticije vrše se klinička i laboratorijska istraživanja...

Увод: Биокомпатибилност се тумачи као способност материјала да делује уз адекватан одговор домаћина у одређеној ситуацији. Одговор домаћина на страно тело зависиће од његове хемијске реактивности, површинске структуре и топографије. Доказано је да наноструктурирана површина ближе подражава хијерархијску организацију коштаног ткива у односу на микроструктурирану, повећањем концентрације активних биомолекула који утичу на ћелијску миграцију, адхезију, диференцијацију и пролиферацију. Током деведесетих година, минерални триоксидни агрегат (МТА) представљен је као материјал избора за ретроградне кавитете због нижег апикалног микропропуштања, везивања у присуству влаге и високе pH вредности. Упркос повољним особинама, МТА показује суву конзистенцију, ниску вискозност и дуго времена везивања, што ограничава његову клиничку употребу. Циљ ове студије био је да се синтетишу наноматеријали на бази веома активних калцијум-силиката унапређених физичко-хемијских својстава и испитају њихова биокомпатибилност и биоактивност у односу на МТА+ (Cerkamed, Stalowa Wola- Пољска). Материјали и Метод: Поступак сол-гел методе у комбинацији са методом високо-температурне ланчане реакције сагоревања примењен је у току синтезе испитиваних материјала. Анализа фаза пре и после хидратација изведена је помоћу XRD и FTIR, док је морфологија узорака проучавана SEM и EDS. pH мерења су обављена коришћењем pH-метра, док је количина ослобођених јона одређивана коришћењем ICP-OES. Биокомпатибилност свежих материјала и њихових екстраката (24h, 7 и 21 дан) је испитана применом индиректног теста (МТТ), директног теста (LDH), теста пролиферације (3H-тимидин) и директном методом (Неутрално црвена). Интеракција директно примeњених испитиваних материјала са пулпним ткивом анализирана је на моделу културе хуманих зуба (15 и 30 дана). Осамнаест заморца служило је за интрамишићну имплементацију стерилних полиетиленских цевчица испуњених испитиваним материјалима (15, 30 и 60 дана). За интракоштани имплантациони тест употребљено је дванаест новозеландских белих зечева подељених у две групе (30 и 90 дана)... Introduction: Biocompatibility is interpreted as the material's ability to act within the adequate host response in a specific situation. The host’s response to foreign body will depend on its chemical reactivity, surface structure and topography. It has been shown that nanostructured surface more closely mimic the hierarchical organization of the bone tissue in comparison to microstructured, by increasing the concentration of active biomolecules that may affect cell migration, adhesion, differentiation and proliferation. During the nineties, mineral trioxide aggregate (MTA) was presented as a material of choice for retrograde fillings because of its lower apical microleakage, setting in the presence of moisture and high pH. Despite some favorable properties, MTA exhibits dry consistency, low flowability and long setting time which limit its clinical use. The aim of this study was to synthesize nanostructured materials based on highly active calcium silicates with enhanced properties and analyze their biocompatibility and bioactivity in comparison to MTA+ (Cerkamed, Stalowa Wola- Poland). Materials and Methods: The sol-gel method in a combination with hightemperature self-propagating reaction was applied for the synthesis of investigated materials. Phase analysis of investigated materials before and after hydratation was performed by XRD and FTIR, while the morphology of the samples was studied by SEM and EDS. The pH measurements were performed using pH-meter, while the amount of released ions was determined using ICP-OES. Biocompatibility of fresh investigated materials and their elutes (24h, 7 and 21 day) was conducted using indirect (MTT), direct test (LDH), proliferation test (3H-thymidine) and direct method (Neutral red). The interaction of directly applied investigated materials with dental pulp tissue was analyzed in an entire human tooth culture model (15 and 30 days). Eighteen guinea pigs received intramuscular sterile polyethylene tubes filled with investigated materials (15, 30 and 60 days). For intraosseous implementation twelve New Zealand white rabbits, divided into two groups (30 and 90 days) were used. Four calvary defects per animal were created with trepan burs and filled with freshly prepared investigated materials. The occurrence of inflammatory responses and hard tissue formation was categorized according to the previously established scores...

Introduction: Biocompatibility is interpreted as the material's ability to act within the adequate host response in a specific situation. The host’s response to foreign body will depend on its chemical reactivity, surface structure and topography. It has been shown that nanostructured surface more closely mimic the hierarchical organization of the bone tissue in comparison to microstructured, by increasing the concentration of active biomolecules that may affect cell migration, adhesion, differentiation and proliferation. During the nineties, mineral trioxide aggregate (MTA) was presented as a material of choice for retrograde fillings because of its lower apical microleakage, setting in the presence of moisture and high pH. Despite some favorable properties, MTA exhibits dry consistency, low flowability and long setting time which limit its clinical use. The aim of this study was to synthesize nanostructured materials based on highly active calcium silicates with enhanced properties and analyze their biocompatibility and bioactivity in comparison to MTA+ (Cerkamed, Stalowa Wola- Poland). Materials and Methods: The sol-gel method in a combination with hightemperature self-propagating reaction was applied for the synthesis of investigated materials. Phase analysis of investigated materials before and after hydratation was performed by XRD and FTIR, while the morphology of the samples was studied by SEM and EDS. The pH measurements were performed using pH-meter, while the amount of released ions was determined using ICP-OES. Biocompatibility of fresh investigated materials and their elutes (24h, 7 and 21 day) was conducted using indirect (MTT), direct test (LDH), proliferation test (3H-thymidine) and direct method (Neutral red). The interaction of directly applied investigated materials with dental pulp tissue was analyzed in an entire human tooth culture model (15 and 30 days). Eighteen guinea pigs received intramuscular sterile polyethylene tubes filled with investigated materials (15, 30 and 60 days). For intraosseous implementation twelve New Zealand white rabbits, divided into two groups (30 and 90 days) were used. Four calvary defects per animal were created with trepan burs and filled with freshly prepared investigated materials. The occurrence of inflammatory responses and hard tissue formation was categorized according to the previously established scores..., Uvod: Biokompatibilnost se tumači kao sposobnost materijala da deluje uz adekvatan odgovor domaćina u određenoj situaciji. Odgovor domaćina na strano telo zavisiće od njegove hemijske reaktivnosti, površinske strukture i topografije. Dokazano je da nanostrukturirana površina bliže podražava hijerarhijsku organizaciju koštanog tkiva u odnosu na mikrostrukturiranu, povećanjem koncentracije aktivnih biomolekula koji utiču na ćelijsku migraciju, adheziju, diferencijaciju i proliferaciju. Tokom devedesetih godina, mineralni trioksidni agregat (MTA) predstavljen je kao materijal izbora za retrogradne kavitete zbog nižeg apikalnog mikropropuštanja, vezivanja u prisustvu vlage i visoke pH vrednosti. Uprkos povoljnim osobinama, MTA pokazuje suvu konzistenciju, nisku viskoznost i dugo vremena vezivanja, što ograničava njegovu kliničku upotrebu. Cilj ove studije bio je da se sintetišu nanomaterijali na bazi veoma aktivnih kalcijum-silikata unapređenih fizičko-hemijskih svojstava i ispitaju njihova biokompatibilnost i bioaktivnost u odnosu na MTA+ (Cerkamed, Stalowa Wola- Poljska). Materijali i Metod: Postupak sol-gel metode u kombinaciji sa metodom visoko-temperaturne lančane reakcije sagorevanja primenjen je u toku sinteze ispitivanih materijala. Analiza faza pre i posle hidratacija izvedena je pomoću XRD i FTIR, dok je morfologija uzoraka proučavana SEM i EDS. pH merenja su obavljena korišćenjem pH-metra, dok je količina oslobođenih jona određivana korišćenjem ICP-OES. Biokompatibilnost svežih materijala i njihovih ekstrakata (24h, 7 i 21 dan) je ispitana primenom indirektnog testa (MTT), direktnog testa (LDH), testa proliferacije (3H-timidin) i direktnom metodom (Neutralno crvena). Interakcija direktno primenjenih ispitivanih materijala sa pulpnim tkivom analizirana je na modelu kulture humanih zuba (15 i 30 dana). Osamnaest zamorca služilo je za intramišićnu implementaciju sterilnih polietilenskih cevčica ispunjenih ispitivanim materijalima (15, 30 i 60 dana). Za intrakoštani implantacioni test upotrebljeno je dvanaest novozelandskih belih zečeva podeljenih u dve grupe (30 i 90 dana)...

The liberalization of the postal services market includes the obligation to implement the public procurement of postal services. This enables adequate market competition for bodies subjected to the Directive on public procurement. Because of mutually incomparable factors that affect the realization of services, proposed research presents a comprehensive analysis of the application of multi-criteria analysis and AHP method in public procurement, when selecting the most economically advantageous tender. The main problem that occurs is the choice of relevant criteria and related sub-criteria that have more or less impact on the postal services provider.

Uvod.Veliki broj studija u svetu govori u prilog tome da su bolesti u vezi sa radom, u prvom redu mišićno-skeletna oboljenja, veoma česta u populaciji stomatologa. Uzrok tome može se naći u činjenici da je stomatološka profesija veoma zahtevna, podrazumeva pružanje pomoći pacijentima u specifičnom radnom okruženju. Stomatolozi inkorporiraju svoje stavove, vrednosti, ponašanje da bi radili u najboljem interesu pacijenta, i postavljaju pacijenta na prvo mesto. Istovremeno često zanemaruju sebe, odnosno položaj tela, stav, navike tokom rada. To sve može imati posledice na opšte zdravlje samih stomatologa. Uvođenjem sedeće radne pozicije, kao i naprednim razvojem opreme, nije se doprinelo redukciji učestalosti mišićno-skeletnog bola kod stomatologa. Optimalna radna pozicija u stomatologiji je i dalje tema istraživanja. Navedene činjenice govore u prilog tome da se dentalna ergonomija kao mlada nauka sve više razvija, i biva predmet sve većeg interesovanja profesionalaca širom sveta. Dentalna ergonomija kroz adaptaciju radnog okruženja i metoda rada omogućava stomatologu i ostalim članovima tima, zdravo, bezbedno i komforno obavljanje njihove profesionalne aktivnosti, uz poštovanje njihovih fizičkih i psihičkih kapaciteta. Cilj istraživanja bio je da se odredi mišićna aktivnost mišića vrata, ramena i leđa tokom stomatološkog pregleda u sedećoj i stajaćoj radnoj poziciji, da se odredi kada tokom radnog veka počinje da se javlja MS bol tokom stomatološkog rada, kao jedan od prvih simptoma bolesti u vezi sa radom, da se ispita učestalost MS bola koji se javlja u različitim regijama tela, kao simptoma bolesti u vezi sa radom, tokom rada kod stomatologa, kao i da se da se odrede preventivne mere. Materijal i metode. Za rešavanje postavljenih ciljeva, istraživanje se realizovalo u dva pravca. Studijom u kojoj su korišćeni specijalno dizajnirani upitnici, su obuhvaćeni radno aktivni stomatolozi i privatnog i državnog sektora, koji žive i rade na teritoriji Srbije, kao i studenti završne godine Stomatološkog fakulteta. Dizajnirani upitnici su obuhvatili 78 pitanja koja su definisala: individualne karakteristike, socio-ekonomske faktore, metod i organizaciju rada, zadovoljstvo poslom, zdravstveno stanje stomatologa, prisustvo i lokalizaciju mišićno-skeletnih oboljenja, primenjen tretman i profilaktičke aktivnosti... Introduction. A large numbers of studies indicate that work related diseases; mostly musculo-skeletal disorders are very frequent among dental professionals. That can be explained by the fact that dental profession is very demanding, involves providing assistance to the patients in a specific work environment. During daily work dentist are fully committed to their patients, in order to offer them professional and quality service and support. At the same time they often neglect themselves, or body position, attitude, habits during the work. It all could have implications on their health. It is very hard for the dentist to find the optimal body posture during their work. Inadequate dentist's working posture is the highest risk factor for development of muskuloskeletal disorders. Suggestions regarding the preferred position for dental work are changing together with the development of dentistry and dental equipment. Development of the sitting position in dentistry was an attempt to eliminate discomfort and fatigue. Unfortunately, the seated working position has not reduced muskuloskeletal disorders in dentistry, and optimal working positions are still topic of discussion. Those facts indicate that dental ergonomics as very young science presents the focus of interests of many professionals. Dental ergonomics is an adaptation of the work environment and working methods of dentist and other members of the team, with full respect of their physical and mental capacities, in order to perform professional activities in healthy, safe and comfortable way. Objective. The aim of this study was to determine the muscle activity of the neck, shoulders and back muscles, during dental examination in sitting and standing dentist's work position, to determine when occurrence of pain begin among dentists during their career, investigate the prevalence of pain during dental work among population of dentists, as well as to identify preventive measures. Material and methods. In order to solve the objectives, the research was realized in two segments. Specially designed questionnaires by the researchers were used in the study...

U ovoj disertaciji predmet istraživanja je rešavanje problema optimizacije resursa javnog poštanskog operatora (JPO). Predložen je model koji optimizuje ograničene resurse, troškove i operativne prihode korišćenjem neparametarske analize, DEA (engl. Data Envelopment Analysis). Testiranje i verifikacija predloženog modela izvršeni su na skupu od 27 JPO iz zemalja Evropske Unije i Srbije. Dobijeni rezultati eksplicitno pokazuju da su postojeći resursi i način kako se oni koriste ključni u postizanju rezultata rada, kao i to kako može da bude definisan efikasan operativni plan. Između ostalog, za slučaj javnog poštanskog operatora u Srbiji, rezultati ukazuju da ne postoji višak u broju zaposlenih, dok je višak prepoznat u ukupnom broju jedinica poštanske mreže. Pored toga, predstavljeno je izvođenje analize evaluacije efikasnosti javnog poštanskog operatora tokom vremena. U disertaciji, predložen je originalni višeulazni i višeizlazni model za merenje troškovne efikasnosti, CE (engl. Cost Efficiency) dostavnih jedinica poštanske mreže. Analizirana je dostavna mreža javnog poštanskog operatora u Srbiji koja uključuje 1,194 dostavne jedinice. Problem brojnosti i heterogenosti ovih jedinica prevaziđen je definisanjem originalnog algoritma za klasterovanje. Ovaj algoritam je obezbedio poređenje efikasnosti uporedivih jedinica, kao i troetapnu analizu: jedinice-klasterimreža. Dobijeni nalaz ukazuje da je posmatrana dostavna mreža troškovno neefikasna (CE=40%). Dalje, dekompozicijom CE objašnjeno je kako nivo troškovne efikasnosti može biti poboljšan. Ilustracije radi, utvrđeno je da najmanje 794 dostavne jedinice imaju mogućnost za poboljšanje samo na osnovu realokacije resursa. Istražen je uticaj ekonomije obima na efikasnost dostavnih jedinica gde je utvrđeno da ona ima jači uticaj na efikanost malih jedinica u poređenju sa velikim jedinicama. Konačno, na osnovu izvedenih rezultata, dato je obrazloženje zašto predloženi model za merenje troškovne efikasnosti može da bude dragoceno sredstvo za kreatore politike i regulatore iz poštanskog sektora, kao i za menadžere poštanskih operatora. Doktorska disertacija, Predrag V. Ralević vi U disertaciji je predstavljen novi koncept univerzalne poštanske usluge. Suština ovog koncepta je mogućnost da se pošiljalac opredeljuje za uslugu koja bi se obavila u roku do 24 časa od vremena predaje pošiljke na prenos ili za drugu vrstu prenosa koji bi podrazumevao duži rok. Na osnovu toga, predstavljene su tri alternative novog koncepta koje ukazuju da se redefinisanjem univerzalne poštanske usluge može doprineti boljoj diversifikaciji ponude poštanskih usluga. Sa druge strane, u slučaju JPO iz Srbije pokazano je da predloženi koncept nove usluge ima pozitivan uticaj sa stanovišta očekivanih prihoda. To potvrđuju rezultati koji su izvedeni korišćenjem analize vremenskih serija, regresione i korelacione analize, teorije difuzije za prognoziranje tražnje za novom poštanskom uslugom (Basov model), kao i metode upitnika i intervjua. In this dissertation the research subject was to solve the problem of resource optimization of Universal Service Provider (USP). The model optimizing the limited resources, expenditure and operating revenue by using nonparametric analysis (DEA) is proposed. The testing and verification of the proposed model were performed on a set of 27 USPs from European Union member states and Serbia. The obtained results explicitly show that existing resources and how they are used are crucial in achieving the performance outcomes as well as to define the efficient operational plan. Among other, in the case of the USP in Serbia, the results indicate that there is not an excess in the number of employees, while the excess is recognized in the total number of permanent post offices. Beside that, in this thesis the derivation analysis of efficiency change over time for universal service provider is presented. In the dissertation, a multiple-input and multiple-output model for measuring the cost efficiency (CE) of postal delivery branches is proposed. The complete postal network of the Serbian Post delivery offices, which includes 1,194 post office branches is analyzed. The problem of numerous and heterogeneous of delivery offices was overcome by defining a new clustering algorithm. This algorithm enable to compare the branches that operate under the same or similar conditions and a three-level analysis: branches-clusters-network. The findings obtained indicate that the observed delivery network is cost inefficient (CE=40%). Furthermore, the explanation of how the level of CE could be improved is given by the decomposition of cost efficiency. For illustration, the results of this thesis indicate that, at a minimum, 794 delivery branches could improve their efficiency by resource reallocation. An impact of the economies of scale to efficiency of delivery branches is investigated and it indicates that the economies of scale have a stronger impact on small branches compared to large units. Finally, based on obtained results, the rational of how suggested model for measuring the cost efficiency can be beneficial to policy makers from the postal sector and to company managers is provided. Doktorska disertacija, Predrag V. Ralević viii In the dissertation a new concept of universal service obligation is presented. The essence of this concept is a possibility that the sender choose a transit time for his/her shipment, should it be within 24h or more. Based on that, three alternatives to the new concept are presented and they indicate that can contribute to a better diversification of offer of postal services. On the other hand, in the case of the USP from Serbia is demonstrated that the proposed concept of new service has a positive impact from the standpoint of expected revenue. This confirms the results derived by using time series analysis, regression and correlation analysis, the diffusion theory for forecasting demand for new postal service (Bass Model) as well as interview and questionnaire methods.

UVOD: U poslednjih nekoliko godina zapaža se porast učestalosti akutnog pankreatitisa (AP) kod odraslih kao i kod dece. Prevalenca AP kod odraslih iznosi od 6–45/100.000 godišnje dok se u dečijoj populaciji kreće od 3,6 do 13,2 slučaja na 100.000 dece. Težina kliničke slike AP varira od blage forme do fulminantne životno ugrožavajuće, praćene brojnim komplikacijama. Zato je nastala potreba za odreĎivanjem novog prognostičkog markera koji može pomoći pedijatrima u predviĎanju toka i ishoda AP. Poremećaji koagulacije koji nastaju u AP mogu biti različitog intenziteta od potrošne koaglopatije pa sve do fatalne diseminovane intravaskularne koagulacije (DIC). U ranije objavljenim studijama ispitivani su različiti parametri hemostaze kao potencijalni prognostički markeri toka i ishoda bolesti. OdreĎivanje nivoa D-dimera, koji se od ranije koriste u kliničkoj praksi kao efikasno dijagnostičko sredstvo za dokazivanje dubokih venskih tromboza i plućne embolije, ima i značajnu ulogu u predviĎanju toka bolesti u ranoj fazi akutnog pankreatitisa. CILJ: Cilj ovog rada je utvrditi ulogu D- dimera u predviĎanju nastanka dve najvažnije lokalne i sistemske komplikacije akutnog pankreatitisa u dece (pseudocista pankreasa i sindrom multiplog popuštanja organa-MOF). TakoĎe smo analizirali korelaciju nivoa D-dimera i kliničkih znakova akutnog pankreatitisa (tahikardija, hipertenzija, ikterus) i ispitivali povezanost izmeĎu nivoa D-dimera i ostalih laboratorijskih pokazatelja aktivnosti akutnog pankreatitisa... BACKGROUND: Recently published articles describe an increasing incidence of acute pancreatitis (AP) in both children and adults. The prevalence of acute pancreatitis is estimated between 6–45 per 100.000 adults per year and between 3,6 and 13,2 cases per 100.000 children. The severity of acute pancreatitis can range from mild disease to a severe life-treatening disease associated with multiple complications.Therefore, there is a need for an ideal prognostic marker of disease severity that can help the pediatricians to predict clinical course and possible outcome of AP. Coagulation abnormalities always occur in AP, ranging from localized intravascular thrombosis to severe disseminated intravascular coagulation (DIC) and are related to disease severity. Several biochemical markers and haemostatic parameters have been used to assess severity and outcome of AP. Some previous studies reported that D-dimer level, commonly used parameter in the diagnosis of deep vein thrombosis as well as pulmonary embolism, have predictive power in the early phase of AP in adults . THE AIM: The aim of this study was to assess the value of the plasma D-dimer level in the prediction of two most inmportant local and sistemic complications of acute pancreatitis in children (pseudocyst fomation and multiple organ failure –MOF). We had also analyzed the correlation between D- dimer level and the presence of clinical signs of acute pancreatitis (tachycardia, hypotension, jaundice) and we examined the connection between D- dimer level and the other laboratory severity markers...

Introduction. A large numbers of studies indicate that work related diseases; mostly musculo-skeletal disorders are very frequent among dental professionals. That can be explained by the fact that dental profession is very demanding, involves providing assistance to the patients in a specific work environment. During daily work dentist are fully committed to their patients, in order to offer them professional and quality service and support. At the same time they often neglect themselves, or body position, attitude, habits during the work. It all could have implications on their health. It is very hard for the dentist to find the optimal body posture during their work. Inadequate dentist's working posture is the highest risk factor for development of muskuloskeletal disorders. Suggestions regarding the preferred position for dental work are changing together with the development of dentistry and dental equipment. Development of the sitting position in dentistry was an attempt to eliminate discomfort and fatigue. Unfortunately, the seated working position has not reduced muskuloskeletal disorders in dentistry, and optimal working positions are still topic of discussion. Those facts indicate that dental ergonomics as very young science presents the focus of interests of many professionals. Dental ergonomics is an adaptation of the work environment and working methods of dentist and other members of the team, with full respect of their physical and mental capacities, in order to perform professional activities in healthy, safe and comfortable way. Objective. The aim of this study was to determine the muscle activity of the neck, shoulders and back muscles, during dental examination in sitting and standing dentist's work position, to determine when occurrence of pain begin among dentists during their career, investigate the prevalence of pain during dental work among population of dentists, as well as to identify preventive measures. Material and methods. In order to solve the objectives, the research was realized in two segments. Specially designed questionnaires by the researchers were used in the study..., Uvod.Veliki broj studija u svetu govori u prilog tome da su bolesti u vezi sa radom, u prvom redu mišićno-skeletna oboljenja, veoma česta u populaciji stomatologa. Uzrok tome može se naći u činjenici da je stomatološka profesija veoma zahtevna, podrazumeva pružanje pomoći pacijentima u specifičnom radnom okruženju. Stomatolozi inkorporiraju svoje stavove, vrednosti, ponašanje da bi radili u najboljem interesu pacijenta, i postavljaju pacijenta na prvo mesto. Istovremeno često zanemaruju sebe, odnosno položaj tela, stav, navike tokom rada. To sve može imati posledice na opšte zdravlje samih stomatologa. Uvođenjem sedeće radne pozicije, kao i naprednim razvojem opreme, nije se doprinelo redukciji učestalosti mišićno-skeletnog bola kod stomatologa. Optimalna radna pozicija u stomatologiji je i dalje tema istraživanja. Navedene činjenice govore u prilog tome da se dentalna ergonomija kao mlada nauka sve više razvija, i biva predmet sve većeg interesovanja profesionalaca širom sveta. Dentalna ergonomija kroz adaptaciju radnog okruženja i metoda rada omogućava stomatologu i ostalim članovima tima, zdravo, bezbedno i komforno obavljanje njihove profesionalne aktivnosti, uz poštovanje njihovih fizičkih i psihičkih kapaciteta. Cilj istraživanja bio je da se odredi mišićna aktivnost mišića vrata, ramena i leđa tokom stomatološkog pregleda u sedećoj i stajaćoj radnoj poziciji, da se odredi kada tokom radnog veka počinje da se javlja MS bol tokom stomatološkog rada, kao jedan od prvih simptoma bolesti u vezi sa radom, da se ispita učestalost MS bola koji se javlja u različitim regijama tela, kao simptoma bolesti u vezi sa radom, tokom rada kod stomatologa, kao i da se da se odrede preventivne mere. Materijal i metode. Za rešavanje postavljenih ciljeva, istraživanje se realizovalo u dva pravca. Studijom u kojoj su korišćeni specijalno dizajnirani upitnici, su obuhvaćeni radno aktivni stomatolozi i privatnog i državnog sektora, koji žive i rade na teritoriji Srbije, kao i studenti završne godine Stomatološkog fakulteta. Dizajnirani upitnici su obuhvatili 78 pitanja koja su definisala: individualne karakteristike, socio-ekonomske faktore, metod i organizaciju rada, zadovoljstvo poslom, zdravstveno stanje stomatologa, prisustvo i lokalizaciju mišićno-skeletnih oboljenja, primenjen tretman i profilaktičke aktivnosti...

Availability of information and services, along with integrity and confidentiality presents a critical parameter in security in information and communication systems. Activities focused on denial of network communication availability are current from the beginning of global communication network development and they demand continuous development of protection methods. Significant challenge is the emergence of the Internet of Things (IoT) concept which will significantly increase the number of connected devices. That kind of environment is possible to use for generation of DDoS attacks. The paper investigates the effect of a significant increase in the number of connected devices in the IoT concept on increase of the number and volume of DDoS attacks.

Oralno zdravlje smatra se važnim delom opšteg zdravlja ljudi, ali je često zanemarena oblast, a razlozi tome su raznovrsni i kompleksni. Visoka učestalost oralnih oboljenja ima veliki socijalni i ekonomski uticaj. Najčešća oboljenja usne duplje su karijes, parodontalna oboljenja i oralne infekcije, dok su glavni uzročnici ovih oboljenja vrste rodova Streptococcus mutans-grupa, Staphylococcus, Lactobacillus, Pseudomonas, Enterococcus i Candida. Efikasan tretman i razvoj novih antiseptika koji poseduju antimikrobnu aktivnost je od velikog značaja za medicinu. Najčešće se koriste preparati koji sadrže hlorheksidin, povidon jod i cetilpiridinijum hlorid, zatim sintetička sredstva kao što su penicilin, cefalosporini, tetraciklini i njihovi derivati, nistatin, amfoterecin B, flukonazol itd. Ovi agensi poseduju antimikrobno dejstvo i kontrolišu upalu desni, ali imaju ograničenu efikasnost i veliki broj negativnih posledica kao što su bojenja zuba, iritacije sluzokože usne duplje, pojave alergije, nefrotoksičnost i endokrinu toksičnost, a povezuju se i sa kancerom i drugim sekundarnim oboljenjima. Problem rezistencije prema Svetskoj zdravstvenoj organizaciji je najveća pretnja globalnom zdravlju čoveka. Jedna od alternativa koja je poslednjih decenija u žiži naučnih interesovanja jesu etarska ulja kao izvor biološki aktivnih jedinjenja. U cilju dobijanja novih biološkli aktivnih jedinjenja, koja neće biti toksična za humane i animalne ćelije, u ovoj disertaciji analiziran je hemijski sastav i biološka aktivnost in vitro 60 komercijalnih uzoraka etarskih ulja ekstrahovano iz 47 biljnih vrsta: Cananga odorata, Foeniculum vulgare, Pimpinella anisum, Pastinaca sativa, Anethum graveolens, Matricaria recutita, Achillea millefolium, Helichrysum italicum, Boswellia carterii, Canarium luzonicum, Commiphora myrrha, Juniperus communis, J. virginiana, Gaultheria procumbens, G. fragrantissima, Pelargonium graveolens, Hyssopus officinalis, Mentha piperita, M. pulegium, Lavandula angustifolia, Thymus algeriensis, T. vulgaris, T. serpyllum, Rosmarinus officinalis, Salvia lavanudilifolia, S. officinalis, S. sclarea, S. triloba, Satureja montana, Laurus nobilis, Leptospermum petersonii, L. scoparium, Eucalyptus citriodora, E. globulus, Melaleuca alternifolia, M. quinquenervia, Syzygium aromaticum, Abies procera, A. grandis, A. alba, Pseudotsuga douglasii, Pinus silvestris, Piper nigrum, Cymbopogon martinii, Rosa centifolia, Citrus aurantium spp. aurantium i C.limon. Cilj rada je ispitivanje biološke aktivnosti i uticaja etarskih ulja i komponenti odabranih aromatičnih biljaka na mikroorganizme izolovane iz usne duplje čoveka i primena u prevenciji i lečenju oralnih bolesti i infekcija. Kvalitativna i kvantitativna analiza uzoraka etarskih ulja vršena je gasnohromatografski korišćenjem GC/MS i GC/FID procedura. Ukupno je identifikovano 342 komponente iz grupa jedinjenja oksidovanih monoterpena, monoterpenskih ugljovodonika, seskviterpenskih ugljovodonika, oksidovanih seskviterpena, fenilpropanoida, spiroetra, alifatičnih ketona, viših alkana, oksidovanih diterpena, alifatičnih ugljovodonika i oksidovana alifatična jedinjenja. U periodu 2010-2011. godine izvršena je izolacija i identifikacija mikroorganizama iz usne duplje pacijena sa Klinike za dečju i preventivnu stomatologiju Stomatološkog Fakulteta, Univerziteta u Beogradu. Antibakterijska aktivnost testirana je na 8 kliničkih izolata (Staphylococcus aureus, Streptococcus pyogenes, Streptococcus mutans, Lactobacillus acidophilus, Streptococcus salivarius, Streptococcus sanguinis, Pseudomonas aeruginosa i Enterococcus feacalis). Antifungalna aktivnost ispitana je na 58 kliničkih izolata (Candida albicans, C. glabrata i C. krusei) i dva referentna soja (C. albicans i C. tropicalis). Antimikrobna aktivnost etarskih ulja određivana je pomoću mikrodilucione i bioautografske metode na TLC pločama. Određivane su minimalne inhibitorne (MIK) i minimalne baktericidne i fungicidne (MBK/MFK) koncentracije. Kao pozitivne kontrole korišćeni su komercijalni antibiotici i mikotici (Ampicilin, Streptomicin i Flukonazol) i preparati za održavanje oralne higijene (Hexoral® i Curasept®), kao i koloidni rastvor srebrne vode i ozona. Rezultati mikrodilucione metode su pokazali da etarsko ulje T. serpyllum poseduje najbolji antibakterijski potencijal, dok su ulja M. recutita1 i J. virginiana pokazala najslabije dejstvo na ispitivane bakterije. Najbolji antifungalni potencijal pokazalo je etarsko ulje S. montana, dok je najslabiju aktivnost imalo etarsko ulje H. italicum2. Prema rezultatima korišćenja bioautografske metode na TLC pločama sva etarska ulja i izolovana jedinjenja pokazala su antimikrobnu aktivnost. Za potvrđivanje antimikrobne aktivnosti i ispitivanje mehanizma dejstva etarskih ulja i komponenti korišćena je skening elektronska mikroskopija (SEM), kojom je potvrđena njihova aktivnost na destabilizacije ćelijske membrane ćelija C. albicans. Korišćenjem kriterijuma jačine antimikrobne aktivnosti etarska ulja odabrana su za ispitivanje međusobne interakcije, antiquorum sensing, antibiofilm i citotoksičnog efekta/potencijala su bila C. limon, P. nigrumZ, M. alternifolia2, T. algeriensis, T. serpyllum, T. vulgaris, G. fragrantissima, P. graveolens, C. limon, R. centifolia, L. petersonii, S. montana, C. martinii i C. myrrha. Međusobne interakcije etarskih ulja i njihovih komponenti testirane su na reprezentativne kliničke izolate S. mutans i C. albicans. Rezultati ispitivanja pokazuju sinergističko, aditivno i antagonističko dejstvo. U okviru antiqourum-sensing aktivnosti, ispitan je uticaj ulja na proces kretanja ćelija P. aeruginosa PAO1 (twiching i flagella test), produkciju piocijanina kao i sposobnost formiranja biofilma. Odabrana etarska ulja su se pokazala vrlo efikasnim u inhibiciji quorum-sensing zavisnih procesa i pokazala jak antiqourum sensing potencijal. Testirane minimalne inhibitorne i sub-inhibitorne koncentracije etarskih ulja inhibirale su proces formiranja biofilma kod S. mutans i C. albicans, u odnosu na kontrolnu grupu. Citotoksičnost etarskih ulja ispitivana je pomoću sulforodamin B testa (Sr-B test) i test redukcije tetrazola (MTT test) na ćelijske linije MCF-7, NCI-H 46, HCT15, HeLa, HepG2, PLP2, LS-174, K562, A549, Fem-X i MRC-5. Kvantifikacijom stepena citotoksičnosti odabranih etarskih ulja, utvrđeno je da pokazuju dejstvo na tumorske ćelijske linije. Prikazana biološka aktivnost odabranih etarskih ulja na mikroorganizme iz usne duplje čoveka ukazuje na mogućnost izrade preparata na bazi etarskih ulja i njegove upotrebe u terapijske i profilaktičke svrhe. Oral health is considered an important part of general health, but is often neglected area, and the reasons for this are diverse and complex. The high incidence of oral disease has a huge social and economic impact. The most common diseases of the oral cavity are dental caries, periodontal disease, and oral infections, while the main causal agents of these diseases are species of genus Streptococcus mutans-group, Staphylococcus, Lactobacillus, Pseudomonas, Enterococcus and Candida. Effective treatment and developing new drugs that have antimicrobial activity is of great significance for medicine. The most commonly used preparations containing chlorhexidine, povidone iodine and cetylpyridinium chloride, followed by synthetic drugs such as penicillin, cephalosporins, tetracyclines and their derivatives, nystatin, amphotericin B, fluconazole, etc. These agents possess antimicrobial activity and control gum inflammation, but have limited efficacy and a large number of negative effects such as tooth staining, mucosal irritation, allergy, nephrotoxicity and endocrine toxicity, and are also associated with cancer and other secondary illnesses. The problem of resistance to the World Health Organization is the biggest threat to global human health. One of the alternatives that in recent decades are in focus of scientific interest are essential oils as a source of biologically active compounds. In order to obtain new biologically active compounds, which will not be toxic to human and animal cells, in this dissertation analysis of the chemical composition and biological activity in vitro of 60 commercial samples of essential oils extracted from 47 plant species were used: Cananga odorata, Foeniculum vulgare, Pimpinella anisum, Pastinaca sativa, Anethum graveolens, Matricaria recutita, Achillea millefolium, Helichrysum italicum, Boswellia carterii, Canarium luzonicum, Commiphora myrrha, Juniperus communis, J. virginiana, G . fragrantissima, Pelargonium graveolens, Hyssopus officinalis, Mentha piperita, M. pulegium, Lavandula angustifolia, Thymus algeriensis, T. vulgaris, T. serpyllum, Rosmarinus officinalis, Salvia lavanudilifolia, S. officinalis, S. sclarea, S. triloba, Satureja montana, Laurus nobilis, Leptospermum petersonii, L. scoparium, Eucalyptus citriodora, E. globulus, Melaleuca alternifolia, M. quinquenervia, Syzygium aromaticum, Abies procera, A. grandis, A. alba, Pseudotsuga douglasii, Pinus silvestris, Piper nigrum, Cymbopogon martinii, Rosa centifolia, Citrus aurantium spp. aurantium and C. limon. The aim was to test their biological activity and the impact of essential oils and components from selected aromatic plants to microorganisms isolated from human oral cavity for the application in the prevention and treatment of oral diseases and infections. Qualitative and quantitative analysis of essential oils Gas chromatographic was performed using GC / MS and GC / FID procedures. A total of 342 compounds were identified belonging to different groups such as oxidized monoterpenes, monoterpenskih hydrocarbons, sesquiterpene hydrocarbons, oxidized sesquiterpenes phenylpropanoids, spiro ethers, aliphatic ketones, higher alkanes, oxidized diterpenes, aliphatic hydrocarbons and oxidized aliphatic compounds. In the period 2010-2011 the isolation and identification of microorganisms from the oral cavity were collected of patients who attend the Clinic for Pediatric and Preventive Dentistry, Faculty of Dentistry, University of Belgrade. The antibacterial activity was tested on 7 clinical isolates of bacteria (Staphylococcus aureus, Streptococcus pyogenes, Streptococcus mutans, Lactobacillus acidophilus, Streptococcus salivarius, Streptococcus sanguinis, Pseudomonas aeruginosa and Enterococcus faecalis). Antifungal activity was investigated on 58 clinical isolates (Candida albicans, C. glabrata and C. krusei) and two reference strains of fungi (C. albicans and C. tropicalis). The antimicrobial activity of essential oils was determined by microdilution and bioautography method on TLC plates. Determination of minimal inhibitory concentrations (MIC) and minimum bactericidal and fungicidal (MBC / MFC) concentration were done. As a positive control we used a commercial antibiotics and antimycotics (Ampicillin, Streptomycin and Fluconazole), and preparations for oral hygiene (Hexoral® and Curasept®), as well as colloidal silver, and a ozone gas. Results from the microdilution method showed that the essential oil of T. serpyllum has the best antibacterial potential, while oil M. recutita1 and J. virginiana showed the lowest effect on the examined bacteria. Best antifungal potential was achived by the essential oil of S. montana, while the lowest activity had essential oil of H. italicum2. According to the results of bioautography method used on TLC plates, all essential oils and isolated compounds showed antimicrobial activity. To confirm the antimicrobial activity and the potential mechanism of action of essential oils and components scanning electron microscope was used, which confirmed their activity on the cell membrane destabilisation to C. albicans. The essential oils with the best antimicrobial activity, as main criteria, were selected for further study as testing interactions, antiquorum sensing, antibiofilm and cytotoxic effect / potential C. limon, P. nigrumZ M. alternifolia2, T.algeriensis, T. serpyllum, T. vulgaris, G. fragrantissima, P . graveolens, R. centifolia, L. petersonii, S. montana, C. martinii and C. myrrha. Mutual interactions of essential oils and their components are tested on a representative clinical isolates of S. mutans and C. albicans. The test results demonstrate the synergistic, additive and antagonistic effects. Within antiqourum-sensing activities, the effects of the oils on the process of moving of P. aeruginosa PAO1 (twiching and flagella test), piocyanin production, as well as the ability to form biofilms were investigated. Selected essential oils have proven very effective in the inhibition of quorum sensing dependent processes and showed strong antiqourum sensing potential. Tested minimum inhibitory and sub-inhibitory concentrations of essential oils were found to inhibit the process of biofilm formation of S. mutans and C. albicans in comparison to the control group. The cytotoxicity of the essential oils was tested using a sulforhodamine B assay (Sr-B test) and the test of the tetrazole salt reduction (MTT assay) in the cell lines MCF-7, NCI-H 46, HCT15, HeLa, HepG2, PLP2, LS-174, K562, A549, Fem-X and MRC-5. The results of the quantification of cytotoxicity of the essential oils selected, it has been found to exhibit the effect on all tumor cell lines. Displayed biological activity of selected essential oils on microorganisms from the oral cavity as man point show the possibility of making preparations based on essential oils and their use in therapeutic and prophylactic purposes.

It is well known that transport significantly contributes to economic growth. Beside positive effect on society, transport, especially road transport has negative impacts such as air pollution, congestion, accidents, noise and climate change. In order to increase energy efficiency in transport, by the introduction of electric bicycles in the postal transport, Croatian Post Inc. contributes to the reduction of negative impact of transport on the environment. This paper examines the impact on the environment by replacing the existing fleet of bicycles in more environmentally friendly form of transport, and the calculation of external costs.

The research presented in this thesis is excellent service in a dental practice. How to define it , how to model , how to develop a model of the dental care system , whose services will have these features . All these aspects should be considered as a model which should be applied in Serbia , where these issues in recent years given special attention , but not in this area , but for some other branches of medicine . For these reasons, this study is of particular importance . The main objective of this research is to develop a model for excellent dental organization that will by itself generate excellent dental care. Today, we have developed models of organizations that manage the quality of their business by applying the model of business excellence . Of course , we're talking about organizations that generate products or services of world class quality . Therefore, the secondary objective of this research is based on the experiences of developed countries , to carry out evaluations dostigntog upravljnja level of quality in the SHC in our country , and that is the basis of designing a model of excellent dental organization that will provide and excellent dental care., Predmet istraživanja u ovoj tezi je izvrsna usluga u stomatološkoj praksi. Kako je definisati, kako je modelirati, kako razviti model organizacije stomatološke zdravstvene zaštite, čija usluga će imati ove karakteristike. Sve ove aspekte treba razmatrati kao model koga treba primeniti u Srbiji, gde se ovim pitanjima u poslednjih nekoliko godina pridaje posebna pažnja, ali ne za ovu oblast, već za neke druge grane medicine. Iz tih razloga ova istraživanja imaju poseban značaj. Osnovni cilj ovih istraživanja je da se razvije model za izvrsnu stomatološku organizaciju koja će sama od sebe da generiše izvrsnu stomatološku uslugu. Danas imamo razvijene modele organizacija koje upravljaju kvalitetom svog biznisa primenjujući modele poslovne izvrsnosti. Naravno, ovde se radi o organizacijama koje generišu proizvode ili usluge svetske klase kvaliteta. Zato je sekundarni cilj ovih istraživanja da se na bazi iskustva iz razvijenih zemalja, izvrši ocena dostigntog nivoa upravljnja kvalitetom u SZZ u našoj zemlji, pa da se na bazi toga projektuje model izvrsne stomatološke organizacije koja će davati i izvrsne stomatološke usluge.

Tkivno inženjerstvo koštanog tkiva se u ovom veku razvilo u jedno od glavnih polja istraživanja u regenerativnoj medicini. Ono predstavlja alternativni pristup u odnosu na konvencionalne koštane transplantate. Osnovni cilj ove vrste terapije je da popravi, regeneriše i rekonstruiše oštećeno ili bolešću zahvaćeno tkivo. Osnovu tkivnog inženjerstva čine ćelijski nosači koji predstavljaju razne vrste biomaterijala sposobnih da učestvuju u regeneraciji koštanog tkiva. Veliki broj materijala je istraživan i analiziran sa ciljem da se koristi kao ćelijski nosač na koji bi mogle da se zasejavaju ćelije. Ćelijski nosač koji bi tim ćelijama omogućio rast, proliferaciju i njihovo unošenje u defekte kosti nakon čega bi novostvoreno tkivo preuzimalo strukturu i funkciju obolelog dela tkiva. Hidroksiapatiti i drugi kalcijum fosfatni materijali imali su široku upotrebu kao koštani zamenici više od dve decenije. Zbog loših mehaničkih osobina poroznih hidroksiapatita došlo je do ograničenja njihove primene. U slučaju kada se kombinuju u kompozitne materijale sa odgovarajućim polimer/biopolimer tankim filmovima, porozni hidroksiapatiti dobijaju optimalne osobine potrebne ćelijskim nosačima, koje mogu pružiti odlične uslove za infiltraciju, rast i aktivnost ćelija neophodnih u tkivnom inženjerstvu kosti. Osnovni cilj doktorske disertacije bio je izvršiti karakterizaciju, ispitati biokompatibilnost i biofunkcionalnost poroznog hidroksiapatita dobijenog modifikovanom hidrotermalnom metodom(pHAP), poroznog hidroksiapatita dobijenog modifikovanom hidrotermalnom metodom u kombinaciji sa PLGA (pHAP+PLGA) i poroznog hidroksiapatita dobijenog modifikovanom hidrotermalnom metodom u kombinaciji sa metforminom (pHAP+metformin). Istraživanje je podrazumevalo karakterizaciju ispitivanih materijala uz pomoć Fourier transform infracrvene spektroskopije (FTIR), metodom rentgen difrakcije (XRD), metodom atomski forsirane mikroskopije (AFM), analizom skening elektronske mikroskopije (SEM) i BET metodom. Biokompatibilnost je ispitivana pomoću MTT testa (indirektni kontakt ispitivanih materijala sa ćelijskom kulturom L 929 fibroblasta), LDH testa (direktni kontakt ispitivanih materijala sa ćelijskom kulturom L 929 fibroblasta) i testom kutane iritacije. Biofunkcionalnost ispitivanih materijala bila je istraživana njihovom implantacijom u defekte kritične veličine od 6 mm u predelu kalvarije kunića. Nakon 12 nedelja životinje su bile žrtvovane, a uzorci tkiva su obrađeni za patohistološku analizu. Optičkom mikroskopijom kvantitativno i kvalitativno obrađivani su sledeći parametri: veličina defekta, prisustvo džinovskih ćelija, prisustvo neoangiogeneze, prisustvo bazofila, postojanje znakova nespecifičnog zapaljenja u tkivu, pojava novostvorene kosti, prisustvo fibroplazije u tkivu i procenat mineralizacije... Since the beginning of this century the bone tissue engineering has developed into one of the essential research fields in reconstructive medicine, as an alternative approach compared with the conventional bone transplants. The main objective of this kind of therapy is to repair, regenerate and reconstruct the damaged or disease-stricken tissue. Tissue engineering is based on scaffolds which are of various biomaterials capable of participating in the process of bone tissue regeneration. A great number of materials has been researched and analyzed so as to be used as a scaffold for cell seeding. Therefore, the scaffold would enable those cells to grow, proliferate and penetrate the bone defects, whereupon the new tissue would take over the structure and function of the damaged tissue. Hydroxyapatites and other calcium phosphate materials were widely used as bone replacements for more than two decades. However, the poor mechanical features of porous hydroxyapatites led to their limited use. In case when they are combined into the compound materials together with polymer/biopolymer thin films, the porous hydroxyapatites acquire optimal characteristics required by scaffolds, which can offer excellent conditions for cell infiltration, growth and activity which is necessary in bone tissue engineering. The main objective of the doctoral dissertation was to carry out the characterization, examine the biocompatibility and biofunctionality of porous hydroxyapatite created by the modified hydrothermal method (pHAP), porous hydroxyapatite created by the modified hydrothermal method in combination with PLGA (Phap + PLGA) and porous hydroxyapatite created by the modified hydrothermal method in combination with metformin (pHAP + metformin). The research included the characterization of the tested materials by means of Fourier transform infrared spectroscopy (FTIR), X-ray distraction method (XRD), atomic forse microscopy method (AFM), scanning electorn microscopy analysis(SEM) and BET method. Biocompatibility was examined by MTT test (indirect contact of the tested materials with the cell culture L 929 fibroblasts), LDH test (direct contact of the tested materilas with the cell culture L929 fribroblasts) and test of local effects on skin in rabbits. Biofunctionality of the examined materials was researched by their implatation into defects of critical size of 6mm in the region of parietal bone in rabbits. After 12 weeks the animals were sacrifised, and tissue samples were prepared for pathohistological analysis. By means of the optical microscopy the following parametres were determined both quantitatively and qualitatively: the size of the defect, the presence of giant cells, the presence of neoangiogenesis, the presence of basophils, the presence of nonspecific inflammation in the tissue, the appearance of the newly created bone, the presence of fibroplasia in the tissue and the percentage of mineralization...