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This paper analyzes the variation in the electrical characteristics of NiTi and stainless steel archwires under exposure to different liquid media and temperatures. The archwires were enclosed in a microfluidic chip to obtain a controlled environment, mimicking oral cavity conditions. Five liquids were selected for testing: artificial saliva, Listerine mouthwash, cinnamon essential oil added to artificial saliva, eucalyptus essential oil added to artificial saliva and orange essential oil added to artificial saliva. Impedance spectroscopy was performed at three temperatures, (25, 37 and 50) °C, and in three different time intervals: at the start of the experiment, after three weeks and after six weeks of exposure. The impedance, its modulus and phase, and Nyquist diagrams were plotted, as well as the root-mean-square (RMS) deviation parameter. The results showed that both materials exhibited comparable responses with small changes over time.

Microfluidics is a science and technology. The scientific aspect deals with the behaviour of fluids in the channels of the micrometre order because the behaviour of fluids on the microscale differs drastically in relation to the macroscale. The technological aspect deals with the production and miniaturization of devices, which consist of microchannels or even nanochannels. Unlike the miniaturization of integrated circuits and microelectromechanical devices, in which the whole device is scaled, for microfluidics only the scaling of the space through which the fluid moves is important. The sensitivity of the device is determined by the minimum amount of microfluid that can be used. The fabrication of microfluidic devices is still far from mass production for which there is already a need. Current fabrication technologies are concentrated on the production of laboratory prototypes or have unsatisfactory characteristics for biomedical applications. The development of new technology that can reconcile mass production and biomedical compatibility is the main thread of this thesis. The use of microfluidic devices in biomedicine with an emphasis on material testing as well as personalization and precise dosing of therapy is one of the hot topics today. In precision dosing, one of the most important roles is played by the mixer or micromixer, because the precision and agility of the entire system depend on its precision. The construction of micromixers is a current topic in today's research laboratories.&nbsp, Микрофлуидика представља науку и технологију. Научни аспекат се бави понашањем флуида у каналима реда микрометра јер се понашање флуида на микроскали драстично разликује у односу на макроскалу. Технолошки аспекат се бави производњом и минијатуризацијом уређаја, који се састоје од микроканала или чак наноканала. За разлику од минијатуризације интегрисаних кола и микроелектромеханичких уређаја, код којих се цео уређај скалира, за микрофлуидику важно је само скалирање простора кроз који се флуид креће. Осетљивост уређаја је одређена најмањом количином микрофлуида који се може користити. Фабрикација микрофлуидних уређаја још је далеко од масовне производње за којом већ постоји потреба. Актуелне технологије фабрикације су прилагођене лабораторијским прототиповима или имају незадовољавајуће карактеристике за биомедицинску примену. Развој нове технологије која може да помири масовну производњу и биомедицинску компатибилност представља главну нит ове тезе. Примена микрофлуидних уређаја у биомедицини са акцентом на испитивање материјала као и персонализацију и прецизно дозирање терапије једна је од најактуелнијих тема данашњице. Код прецизног дозирања једну од важнијих улога игра микро мешач односномикромиксер, јер од његове прецизности зависи прецизност и агилност читавог система. Конструкција микро мешача је актуелна тема у данашњим истраживачким лабораторијама., Mikrofluidika predstavlja nauku i tehnologiju. Naučni aspekat se bavi ponašanjem fluida u kanalima reda mikrometra jer se ponašanje fluida na mikroskali drastično razlikuje u odnosu na makroskalu. Tehnološki aspekat se bavi proizvodnjom i minijaturizacijom uređaja, koji se sastoje od mikrokanala ili čak nanokanala. Za razliku od minijaturizacije integrisanih kola i mikroelektromehaničkih uređaja, kod kojih se ceo uređaj skalira, za mikrofluidiku važno je samo skaliranje prostora kroz koji se fluid kreće. Osetljivost uređaja je određena najmanjom količinom mikrofluida koji se može koristiti. Fabrikacija mikrofluidnih uređaja još je daleko od masovne proizvodnje za kojom već postoji potreba. Aktuelne tehnologije fabrikacije su prilagođene laboratorijskim prototipovima ili imaju nezadovoljavajuće karakteristike za biomedicinsku primenu. Razvoj nove tehnologije koja može da pomiri masovnu proizvodnju i biomedicinsku kompatibilnost predstavlja glavnu nit ove teze. Primena mikrofluidnih uređaja u biomedicini sa akcentom na ispitivanje materijala kao i personalizaciju i precizno doziranje terapije jedna je od najaktuelnijih tema današnjice. Kod preciznog doziranja jednu od važnijih uloga igra mikro mešač odnosnomikromikser, jer od njegove preciznosti zavisi preciznost i agilnost čitavog sistema. Konstrukcija mikro mešača je aktuelna tema u današnjim istraživačkim laboratorijama.

Purpose: The purpose of this study was to quantify the elastic properties and evaluate microscopical features of raw and boiled metatarsal bovine bone. Methods: The elastic modulus, hardness and microscopic surface of raw and cooked bovine metatarsal bone have been investigated using nanoindentation, SEM/EDX and Panasis microscope. Results: Regarding raw bovine bone, the average elastic modulus was 30.515 ± 6,769 GPa, while the average hardness was 0.5683 ± 0.211 GPa. When it comes to boiled bone corresponding values were 22.298 ± 7.0303 GPa and 0.408 ± 0.199 GPa, respectively. The values for investigated parameters were significantly higher ( p < 0.05) in raw bone specimens. Elastic modulus significantly correlated with hardness ( p < 0.05). EDX analysis revealed significant decrease in wt% of oxygen in boiled samples ( p < 0.05) No significant differences could be observed in SEM images particularly when analysing in smaller magnifications. Using higher magnification, additional branching of the existing voids as well as discrete reorganization and smoother edges of nutrient canals could be observed. The surface of boiled specimens was without the presence of crusts and layering, and no microscopical evidence of structural damage could be observed. Conclusions: This study provides detailed analysis of hardness, elastic modulus of raw and cooked bovine bone and their relation and changes during exposure to temperature. These results of elastic moduli and hardness could be comparable to similar studies of bovine and human bone tissue, but the careful analysis of experimental design, type of the bone as well as limitations of the employed techniques must be carried out before interpolation of the results to other theoretical, clinical, biomaterial and archeological studies.

In graphic and printing industry coatings are applied on the surface of different materials for providing decorative, protective and/or functional characteristics of prints. In order to produce functional coatings with various scents, and thus enabling value-added printed products, fragranced microcapsules, which can be applied onto different substrate materials, are often added. Functionality, i.e. activation of fragranced microcapsules is achieved by rubbing the surface of the functional coating (use of specific amount of pressure and shear force), under which microcapsules’ shells rupture, releasing the encapsulated fragrance. This research aims to investigate the physical and the mechanical properties of produced functional coatings using water-based varnish and different concentrations of fragranced microcapsules in it. The amount of added fragranced microcapsules strongly affects the functionality of the applied coating. Conducted SEM (scanning electron microscopy) and nanoindentation analyses of the applied functional coatings revealed that different concentrations of added fragranced microcapsules in water-based varnish, significantly affected both physical and mechanical characteristics of the prints.

Purpose: The objective was to assess the effect of fissure depth and enamel surface preparation protocols on penetration of resin-based, giomer and glass-ionomer fissure sealants. Materials and Methods: Ninety extracted third molars were assigned into three groups according to the material used. All three groups were subsequently divided depending on tooth preparation: no pretreatment or surface preparation with 10% polyacrylic acid, 37% phosphoric acid, or self-etching adhesive. In addition, Er,Cr:YSGG laser or air abrasion were employed in all subgroups. The penetration was evaluated using scanning electron microscopy. Results: The groups that were pretreated with an appropriate acid resulted in superior penetration of glass-ionomer and resin-based sealants when compared with other surface preparation protocols (p lt 0.05). The exception was teeth treated with both air abrasion and acid etching. Both preparation protocol and fissure depth significantly affected the sealant penetration (p lt 0.05), but fissure depth had a greater impact on fissure penetration than did enamel surface pretreatment. Conclusion: All investigated materials exhibit similar properties regarding sealant penetration. Penetration of a fissure sealant is significantly influenced by the fissure depth. In regard to enamel surface preparation protocol, a pretreatment with phosphoric acid in resin-based and polyacrylic acid in glass-ionomers appears to be essential in obtaining the adequate penetration of a sealing material.

Purpose: The purpose of this study was to quantify the elastic properties and evaluate microscopical features of raw and boiled metatarsal bovine bone. Methods: The elastic modulus, hardness and microscopic surface of raw and cooked bovine metatarsal bone have been investigated using nanoindentation, SEM/EDX and Panasis microscope. Results: Regarding raw bovine bone, the average elastic modulus was 30.515 +/- 6,769 GPa, while the average hardness was 0.5683 +/- 0.211 GPa. When it comes to boiled bone corresponding values were 22.298 +/- 7.0303 GPa and 0.408 +/- 0.199 GPa, respectively. The values for investigated parameters were significantly higher (p lt 0.05) in raw bone specimens. Elastic modulus significantly correlated with hardness (p lt 0.05). EDX analysis revealed significant decrease in wt% of oxygen in boiled samples (p lt 0.05) No significant differences could be observed in SEM images particularly when analysing in smaller magnifications. Using higher magnification, additional branching of the existing voids as well as discrete reorganization and smoother edges of nutrient canals could be observed. The surface of boiled specimens was without the presence of crusts and layering, and no microscopical evidence of structural damage could be observed. Conclusions: This study provides detailed analysis of hardness, elastic modulus of raw and cooked bovine bone and their relation and changes during exposure to temperature. These results of elastic moduli and hardness could be comparable to similar studies of bovine and human bone tissue, but the careful analysis of experimental design, type of the bone as well as limitations of the employed techniques must be carried out before interpolation of the results to other theoretical, clinical, biomaterial and archeological studies.

Cone-beam computed tomography (CBCT) is a new technology in the field of intraoral imaging which allows 3D visualization of the areas scanned. The aim of our study was to assess the capabilities of CBCT in assessment of dental status, crown and root morphology, dental pathologies, tooth wear and enamel hypoplasia in a sample of 117 teeth from Mesolithic (9000 - 6400 calBC) and Neolithic (6200 - 5300 calBC) individuals from the Central Balkans. The study was carried by CBCT imaging of one root teeth placed in wax rim and stone cast to obtain digital images and 3D reconstructions for odontological assessment. All of the 117 teeth examined showed morphological similarity, similar color, shape, mesio-distal ratio and the presence of significant tooth wear. A few specimens displayed signs of radicular and apical pathology and infractions. In 17 teeth the presence of multiple root canals has been confirmed. Enamel hypoplastic defects were clearly observed and accurate measurements performed in order to evaluate the severity of hypoplasia. The use of CBCT supports the information obtained from archeological, anthropological and DNA investigations. It would seem that there is potential for significant development to be made in the research of paleodontological material using non invasive techniques such as CBCT that could play a crucial role in the investigation of bioarchaeological remains.

The physical properties of bone tissue have been investigated at different levels, macro, micro and nano scale. The aim of this study was to assess the influence of two specimen preparation techniques and six nanoindentation protocols on modulus and hardness of bovine bone specimens. Embedding in resin do not affect the mechanical properties of bone samples. More precise and repeatable results are obtained using higher indentation forces. Larger number of measurements are required for bone indentation analysis using lower forces.

Digitalne radiografije zajedno sa kompjuterizovanom tomografijom (CBCT) su tehnologije široko korišćene u svakodnevnoj kliničkoj praksi sa rastućim interesovanjem za antropološka istraživanja zbog neinvazivne prirode intraoralnih radiografskih tehnika i slike koja omogućava 3D vizuelizaciju skeniranih zubnih i koštanih struktura. Postoje različite tehnike za preciznu procenu starosti zasnovane na zubnim parametrima. Cilj ove studije je bio da se proceni preciznost dve različite tehnike procene radiološke starosti, indeksa krunice zuba (TCI) i Kvaal metode. Uzorak se sastojao od 23 ekstrahovana jednokorena zuba osoba poznate starosti i pola. Zubi su prvo fotografisani i numerisani za objektivnu, slepu evaluaciju. Studija je sprovedena korišćenjem digitalnih radiograma i CBCT snimaka zuba fiksiranih u voštanim grebenima na gipsanom modelu kako bi se dobile digitalne fotografije i 3D rekonstrukcija za radiografsku evaluaciju. Visina krunice i visina pulpe su beleženi za TCI, dok su visina i širina na tri različita nivoa određivani za Kvaalov metod. Utvrđeno je da je TCI tačniji u poređenju sa Kvaalovom metodom. Upotreba CBCT-a i digitalnih radiografija može da podrži nalaze dobijene iz stomatoloških kliničkih, arheoloških, DNK i antropoloških istraživanja.

Makroskopskom analizom kremiranih ljudskih ostataka moguće je dobiti osnovne antropološke informacije, kao i podatke o procesu kremiranja i o obredu koji ga je pratio. Međutim, najčešće su podaci veoma oskudni usled delovanja vatre koja transformiše kosti i dovodi do velike fragmentovanosti i loše očuvanosti skeleta. Budući da je broj informacija dobijenih makroskopskom analizom ograničen, neophodan je interdisciplinarni pristup koji omogućava bolju interpretaciju i razumevanje kremiranih ljudskih ostataka. Ovakav pristup analizi ljudskih i životinjskih ostataka iz pet urni i jedne sahrane van urne, sa lokaliteta Konopište, omogućio nam je da rekonstruišemo temperaturu koja je postignuta na lomači, broj individua koje su sahranjene u jednoj urni, kao i to koje životinje su predstavljale deo obreda. Pored toga, primenom SEM-EDX analiza detektovana je vrsta metala prisutnog u tragovima na kostima, kao i hemijski sastav fragmentovanih artefakata koji su usled vatre doživeli visok stepen destrukcije i gde je makroskopski bilo nemoguće utvrditi kojoj vrsti materijala su pripadali. Osteološki materijal sa lokaliteta Konopište pripada periodu kasnog bronzanog doba i periodu prelaska iz bronzanog u gvozdeno doba.