A antibioticoterapia em cirurgias de terceiros molares inferiores inclusos e/ou impactados é um assunto controverso no meio odontológico. O objetivo do presente estudo foi elucidar a real necessidade de prescrição de antibióticos nestes tipos de cirurgias realizadas por três operadores com experiências clínicas distintas. Um especialista, uma doutoranda e um aluno do último ano da graduação realizaram 50 cirurgias cada um, todas com remoção de osso e alto grau de dificuldade. Antibióticos não foram prescritos nos períodos pré e pós-operatório. No período préoperatório, 2o e 7o dias pós-operatórios foram analisados os seguintes parâmetros: dor, edema, trismo, temperatura corpórea, níveis de proteína C-reativa e contagem de neutrófilos salivares. Durante a cirurgia foram analisados: pressão arterial sistólica, diastólica e média, oximetria, freqüência cardíaca, qualidade da anestesia, quantidade de anestésico local, sangramento, dificuldade e tempo de duração da cirurgia. No dia da retirada de pontos, 7o dia pós-cirúrgico, foi avaliada a qualidade de cicatrização e os voluntários relataram a avaliação global do período póscirúrgico. Não houve nenhum caso comprovado de alveolite ou outro tipo de infecção no local operado. O tempo de cirurgia do graduando e da doutoranda mostraram valores médios maiores que os do especialista (p<0,05). Houve diferença estatisticamente significativa entre o graduando e os outros dois operadores nos seguintes parâmetros: qualidade da anestesia, quantidade de tubetes utilizados, sangramento no momento da incisão, trismo e dor em vários momentos pósoperatórios (p<0,05). Não houve mudanças significativas nos parâmetros hemodinâmicos durante as cirurgias. Os voluntários operados pela doutoranda tiveram uma recuperação da abertura de boca melhor que os operados pelos outros dois operadores (95,88±1,67% para a doutoranda, 86,87±2,05% para o especialista e 79,51±3,05% para o graduando, p<0,05). Houve diferença estatisticamente significativa nos níveis de proteína C-reativa no 2o dia de pós-operatório entre o graduando e o especialista e entre o graduando e a doutoranda (20,39±2,77 mg/L, 18,83±3,94 mg/L e 9,31±0,68 mg/L, respectivamente, p<0,05) e na contagem de neutrófilos salivares no 2o dia de pós-operatório entre os voluntários operados pelo graduando e os operados pela doutoranda (248±41,01 e 78,40±14,51 respectivamente, p<0,05). Os voluntários operados pela doutoranda avaliaram mais positivamente o período pós-cirúrgico em relação àqueles operados pelos outros dois operadores, possivelmente pela menor força e maior delicadeza exercida no momento da cirurgia. A análise conjunta dos resultados obtidos nesta pesquisa permite concluir que a antibioticoterapia mostra-se desnecessária em cirurgias de terceiros molares com necessidade de osteotomia independentemente da experiência do operador. / The use of antibiotics in lower third molar surgeries with necessity of boné removal is controversial. The aim of this study was to elucidate the real necessity of antibiotics prescription in such types of surgeries performed by three different surgeons with distinct clinical experiences. A specialist, a PhD student and a senior dental student performed 50 surgeries each, all with osteotomy and high degree of difficulty. Antibiotics were not prescribed either before or after surgeries. In the preoperatory period and on the second and seventh postoperative days, the following parameters were analyzed: pain, swelling, trismus, body temperature, C-reactive protein levels and salivary neutrophil count. During the surgeries the following parameters were analyzed: systolic, diastolic and mean arterial pressure, oxymetry, heart rate, quality of anesthesia, amount of local anesthetic, bleeding, surgery difficulty and duration of surgery. At the suture removal, seventh postoperative day, quality of wound healing and global evaluation performed by the patient were recorded. There was no confirmed case of dry socket or another type of local infection in the study. The duration of surgeries performed by the senior student and the PhD student showed higher values as compared to the specialist (p<.05). There was statistically significant difference between the senior student compared to both surgeons in the following parameters: quality of anesthesia, amount of local anesthetic, bleeding at incision time, trismus and pain at several postoperative times (p<.05). There were no significant changes in hemodynamic parameters during the surgeries. The PhD students volunteers had better recovery of mouth opening in comparison with the volunteers of the other surgeons (95.88±1.67% for the PhD student, 86.87±2.05% for the specialist, and 79.51±3.05% for the senior student, p<.05). There was significant statistically difference in C-reactive protein levels between the senior student and the specialist, and between the senior student and the PhD student (20.39±2.77 mg/L, 18.83±3.94 mg/L and 9.31±0.68 mg/L, respectively, p<.05), and in salivary neutrophil counts on the second postoperative day between the senior students patients and the PhD students patients (248±41.01 and 78.40±14.51 respectively, p<.05). The PhD students volunteers evaluated the postoperative period more positively in comparison to the volunteers of the other surgeons. Taken together, the results of the present work allow to conclude that antibiotics prescription is not necessary in lower third molar removal with osteotomy regardless of the surgeons experience.

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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A ExtraÃÃo do terceiro molar à um procedimento comum, freqÃentemente associado com dor de intensidade de moderada ou grave, e que afeta um nÃmero significante de pacientes, o que torna os estudos clÃnicos que avaliam a dor associada com a exodontia dos terceiros molares relativamente fÃceis de se executar. O objetivo deste estudo foi determinar a eficÃcia e a seguranÃa da combinaÃÃo terapÃutica de piroxicam, dexametasona, citrato de orfenadrina e cianocobalamina (RheumazinÂ) em comparaÃÃo ao piroxicam isoladamente (FeldeneÂ) em um modelo de cirurgia do terceiro molar inferior. Neste estudo, que foi do tipo randomizado e duplo cego, foram incluÃdos oitenta pacientes selecionados para a exodontia do terceiro molar inferior. Os pacientes receberam Rheumazin ou Feldene 30 min depois da extraÃÃo do terceiro molar inferior e, a partir daÃ, uma vez ao dia durante 4 dias sucessivos. A intensidade da dor foi determinada por meio de uma escala visual analÃgica e pela quantidade de medicaÃÃo de escape utilizada pelos pacientes (paracetamol). O edema facial foi avaliado atravÃs de medidas da face usando uma escala mÃtrica calibrada (mm). Ainda, foram tambÃm avaliados os efeitos adversos e o grau de satisfaÃÃo em relaÃÃo aos tratamentos, ambos relatados pelos pacientes. Embora os resultados tenham mostrado que nÃo houve diferenÃa estatÃstica no edema facial entre os dois grupos, Rheumazin reduziu a dor na 6a e 120a h de tratamento. Rheumazin tambÃm demonstrou um melhor perfil de seguranÃa, prevenindo efeitos adversos tais como nÃusea, indisposiÃÃo e dor epigÃstrica, dentre outros, quando comparado ao FeldeneÂ. Este achado torna o Rheumazin uma boa opÃÃo para o tratamento no pÃs-operatÃrio da remoÃÃo do terceiro molar inferior. / Third molar extraction is a common procedure with pain frequently moderate or severe in intensity, and with sufficient numbers of patients to make studies relatively easy to perform. The aim of this study was to determine the efficacy and the safety of the therapeutic combination of piroxicam, dexamethasone, orphenadrine citrate and cyanocobalamin (RheumazinÂ) in comparison to piroxicam alone (FeldeneÂ) in a mandibular third molar surgery model. Eighty patients selected for removal of the third molar were included in this study which was randomized and double blind. They received Rheumazin or Feldene po 30 min after tooth extraction and once daily for 4 consecutive days. Pain was determined by a visual analogue scale and by the need for escape analgesia (paracetamol). Facial swelling was evaluated using a tape measuring method. Record of adverse effects and patientâs satisfaction was also considered. Although the results showed that there was no statistically significant difference in facial swelling between the two groups, Rheumazin reduced pain at 6th and 120th h of treatment. Rheumazin also demonstrated a better safety profile preventing adverse effects including nausea, indisposition and epigastric pain, among others, when compared to FeldeneÂ. This fact makes Rheumazin a good choice for post-surgery treatment in third molar removal

O desenvolvimento de novos materiais a partir de elementos biodegradáveis com durabilidade considerável, versatilidade apreciável e baixo custo tem grande interesse na aplicação da bio-eletrônica. O presente trabalho objetiva a caracterização das propriedades físicas e químicas das membranas de quitosana obtidas a partir da neutralização da solução policatiônica de quitosana. O trabalho foi dividido em duas etapas: solubilização e neutralização. Na primeira etapa a quitosana foi solubilizada em três concentrações diferentes de ácido acético (1%, 0.8% e 0.5%) para avaliar se a concentração de ácido exerce diferença significativa nas propriedades físico-químicas das membranas de quitosana. Na segunda etapa o policátion de quitosana foi neutralizado com duas bases fortes (NaOH e KOH) em três concentrações molares diferentes (0.5, 1 e 5 molar) pelo método de gotejamento lento da base até atingir o pH de 6.0 no policátion e obter membranas com pH perto da neutralidade. A caracterização das membranas obtidas a partir do policátion de quitosana neutralizado mostrou que as concentrações de ácido acético não mudam de forma significativa as propriedades físico-químicas das membranas. Em contraste, o processo de neutralização afetou as propriedades físico-químicas das membranas, e em particular, diferentes comportamentos foram observados dependendo da base utilizada. Membranas mais dúcteis foram obtidas após neutralização com KOH, exibindo capacidade plastificante pela base usada, enquanto que as membranas neutralizadas com NaOH apresentam um comportamento frágil. Além disso, as membranas neutralizadas com KOH exibem uma maior condução iônica em relação às propriedades elétricas das membranas, o qual pode ser interessante no desenvolvimento de biossensores ou célula combustível. / The development of new materials from biodegradable elements with considerable durability, versatility and low cost is of great interest for applications in bioelectronics. The present work aims the characterization of the chemical and physical properties of chitosan membranes after neutralization of the polycation solution of chitosan. This work was divided into two steps: solubilization and neutralization. In the first step, the chitosan was solubilized with three different concentrations of acetic acid (1%, 0.8% and 0.5%) in order to evaluate whether the acid affects the physical-chemical properties of the chitosan films. In the second step, the polycation of chitosan was neutralized with two different strong bases (NaOH and KOH) using three different molar concentrations (0.5, 1 and 5), by the slow drip method of base until reaching a pH of 6.0 for the polycation and obtaining films with pH close to neutrality. The characterization of the membranes obtained from neutralized chitosan showed that the different concentrations of acetic acid did not affect the physical-chemical properties of the films significantly. In contrast, the neutralization process did affect the physical-chemical properties, and particularly, different behaviors were observed depending on the type of base used for neutralization. More ductile films were obtained after neutralization with KOH, exhibiting plastificant capacity by the used base, whereas the films neutralized with NaOH exhibited a more fragile behavior. Beyond this, regarding the electrical properties, the films with KOH presented a higher ionic conductivity, which could be interesting for developing biosensors or fuel cells.

Les turbines aéronautiques et terrestres utilisent comme matériaux de structure les superalliages à base nickel. Ils sont confrontés en utilisation à des environnements agressifs à très hautes températures, conduisant à l'usure et la corrosion, et à des sollicitations mécaniques qui entraînent fatigue et fluage. Pour permettre l'utilisation de ces matériaux dans des conditions toujours plus sévères de fonctionnement et augmenter la durée de vie des pièces, divers traitements de nitruration ont été proposés pour durcir la surface tout en conservant ou en améliorant la tenue mécanique et la résistance chimique. Les modifications induites par la nitruration, leur stabilité et l'influence de la microstructure initiale sont encore mal comprises dans ces matériaux complexes. Au cours de ces travaux, nous avons étudié les effets d'une nitruration assistée plasma en fonction de la microstructure et de la composition chimique des alliages. Différents types de superalliages à base nickel ont été choisis, de microstructures variées, comprenant éventuellement des précipités de type Ni3(Al,Ti,Nb) et/ou Ni3 (Nb). Nous avons alors caractérisé les modifications induites par l'introduction de l'azote dans les matériaux suite à un traitement de nitruration à basse température (400°C) : expansion de la maille, génération de contraintes résiduelles, comportement des précipités, formation de nitrures, plasticité, anisotropies... Les résultats obtenus suggèrent des effets différents selon la composition des précipités. Ces modifications structurales et leurs évolutions ont ensuite été étudiées lors d'un recuit à plus haute température (650°C) afin d'étudier la stabilité des couches formées. / Nickel-based superalloys are commonly used in pressurized water heat exchangers or in the hottest sections of aeroengines or industrial gas turbines, where they are subjected to high temperature and severe mechanical solicitations (fatigue, creep). To allow use of those materials in more and more difficult operating conditions and to improve their duration, different nitriding treatments have been proposed to harden the surface while maintaining or improving their mechanical strength and chemical resistance. However, modifications induced by nitriding, resulting stability in time and influences of the initial microstructure are still poorly understood in these complex materials. In this work, we investigated the behavior of plasma nitriding on superalloys according to their initial microstructure and chemical composition. Thus, different types of Nickel-based superalloys were selected with various microstructures, possibly including precipitates like Ni3(Al, Ti, Nb) and/or Ni3(Nb). Then, we have characterized the modifications induced by nitrogen introduction in the materials after nitriding treatment at low temperature (400°C): lattice expansion, generation of residual stress, precipitates behavior, nitrides formation, plasticity, anisotropy... The results suggest different behaviors depending on the composition of precipitates. Finally, these structural modifications and their evolutions have been studied during an annealing at higher temperature (650°C) in order to study the stability of the nitrided layers.

Les études de libération de substance active à partir de système polymériques tels que des microparticules à base d’acide poly(lactique-co-glycolique) (PLGA) ont été largement explorées au cours de ces dernières décennies . L’objectif principal de ce travail consiste à mieux comprendre les mécanismes de transport de masse contrôlant la libération de substance active à partir des microparticules de PLGA. Un nouvel aperçu devait être acquis sur la base de suivi expérimental de la cinétique de gonflement de microparticules. Dans un premier temps, des microparticules à base de PLGA chargées de différents types de substances actives (acide, base et neutre), tels que kétoprofen, prilocaine base libre et dexamethasone ont été préparées par simple émulsion (huile dans eau) en utilisant une méthode d'extraction/évaporation du solvant. Les microparticules obtenues avaient des taux d’efficacité d’encapsulation qui sont variables selon la substance active utilisée. Une caractérisation des propriétés clés des microparticules obtenues a été réalisée en utilisant différentes techniques (microscopie optique, microscopie électronique). La chromatographie par permeation de gel a été utilisé pour déterminer le poids moléculaire du PLGA après exposition des microparticules au milieu de libération à différents temps afin d’évaluer la cinétique de dégradation du polymère. La diffraction des rayons X et la calorimétrie différentielle à balayage étaient utilisés pour étudier l’état physique du polymère, de la substance active pure ainsi que les microparticules chargées en substance active. Les études de libération ont montré deux types de profils de libération : un profil tri-phasique et un profil plus ou moins mono-phasique. Le profil tri-phasique observé est constitué de trois phases : une phase de libération initiale rapide suivie d’une libération constante qui est suivie ; à son tour ; par une seconde phase de libération rapide. En revanche, les différentes phases étaient difficilement distinguées pour le deuxième type de profil obtenu, du fait de la libération rapide de substance active ce qui permet de dire que les profils obtenus étaient plus ou moins mono-phasique. L’élucidation des mécanismes de libération de substance active était basée sur le suivi expérimental de la cinétique de gonflement des microparticules. Comme pour les cinétiques de libération obtenues à partir des microparticules à base de PLGA, différentes phases peuvent être distinguées pour les profils de gonflement. Les transitions d’une phase à une autre semblent s’accorder entre le profil de libération et celui du gonflement. Ainsi, le gonflement des microparticules pourrait contribuer au contrôle de la libération de la substance active à partir des microparticules à base de PLGA. / The drug release studies from polymeric system such as Poly(lactic-co-glycolic) acid (PLGA)-based microparticles have been widely investigated during recent decades. The main objective of this work is to better understand the mass transport mechanisms controlling the drug release kinetics from PLGA microparticles. New insight was to be gained based on the experimental monitoring of the swelling kinetics of single microparticle. Initially, PLGA microparticles containing different type of drugs (acidic, basic and neutral), such as ketoprofen, prilocaine free base and dexamethasone were prepared using simple oil in water emulsion extraction/evaporation solvent technique. The characterization of the key properties of microparticles was performed using different techniques (optical microscopy, electron microscopy). The gel permeation chromatography was used to determine the molecular weight of PLGA following exposure of microparticles to the release medium at various times to assess the kinetic degradation of the polymer. The X-ray diffraction and differential scanning calorimetry were used to study the physical state of the polymer, drug and drug-loaded microparticles. Release studies have shown two types of release profiles: tri-phasic and more or less mono-phasic profile. The tri-phasic profile is composed of three phases: an initial rapid release phase followed by a constant release which is followed by a second phase of rapid release. In contrast, at the investigated higher initial drug loadings, different release phases could hardly be distinguished: The profiles were more or less mono-phasic. The elucidation of drug release mechanisms was based on the experimental results of the swelling kinetics of single microparticles. As for drug release, distinct phases can be distinguished for microparticles swelling. The transition from one phase to another seem to coincide for microparticle swelling and drug release. Thus also microparticle swelling might contribute to a significant extent to the control of drug release.

Predložená diplomová práce se zabývá syntézou biodegradabilních polyuretanu (bio-PU) na bázi polyethylenglykolu (PEG-u) a polykaprolaktonu (PCL) pro využití k medicínským úcelum. Cílem práce bylo vyvinout metodiku prípravy elastomerního polyuretanu, ze kterého by se dal v budoucnu pripravit skafold (nosic bunek) použitelný v tkánovém inženýrství pro humánní regenerativní medicínu. Teoretická cást práce shrnuje informace o materiálech využitelných pro zamýšlenou aplikaci. Zahrnuty jsou také techniky prípravy skafoldu, jejich biokompatibilita a charakterizace vlastností výsledného materiálu. Praktická cást je pak zamerena na navržení vhodné metodiky pro prípravu funkcních vzorku obsahujících PEG, PCL, hexamethylen-diisokyanát (HMDI) a ethylhexanoát cínatý jako katalyzátor. U pripravených vzorku byl zjištován vliv jejich složení (predevším ruzný obsah a molekulová hmotnost PEG-u) na botnání a hydrolytickou stabilitu spolecne s testováním mechanických vlastností, sledováním kinetiky sítování a stanovením stupne konverze. Morfologie vzorku byla sledována pomocí optické mikroskopie, chemické složení bylo potvrzeno infracervenou spektroskopií a tepelné vlastnosti byly urceny diferencní kompenzacní kalorimetrií. Vývoj v metodice prípravy ukázal, že je nezbytné odstranit pred syntézou z výchozích látek veškeré necistoty, predevším vodu a kyslík, jinak vznikaly nedokonale zreagované vzorky s velkým obsahem póru ruzných velikostí. Syntéza všech vzorku probíhala pod dusíkovou atmosférou ve dvou krocích, kdy v prvním se pouze homogenizovaly oba polyoly (PEG i PCL) na vakuové lince pri 130 °C a ve druhém pak vznikaly výsledné bio-PU za pridání HMDI pri 65 °C v inertní atmosfére manipulacního boxu. Vzorky pak byly dopolymerovány ve forme pri 65 °C pod dobu 48 hodin v sušárne. Ruzné fyzikální podmínky metodiky vedly k príprave jak nepruhledných bílých filmu, tak i vzorku s viditelnou separací fází až po flexibilní transparentní filmy. Pozorování optickým mikroskopem vzorku s fázovou separací prokázalo prítomnost sférolitické struktury krystalické fáze PCL v amorfní fázi matrice PEG-u. Sledování kinetiky sítování pomocí soxhletovy extrakce potvrdilo maximální konverzi polymerace (96 %) již za 4 h dopolymerování v sušárne. Testování zkouškou v tahu ukázalo, že výrazný vliv na pevnost v tahu má isokyanátový index (pomer NCO/OH skupin). Molekulová hmotnost PEG-u ovlivnovala pevnost v tahu jen u vzorku zcela zesítovaných. Merení botnání vzorku ve vode prokázalo, že s rustem molekulové hmotnosti PEG-u roste i obsah vody (od cca 28 až po 58 hm.%) ve vzorcích. Také degradace filmu ve vode pri 37 °C probíhala dle predpokladu rychleji u vzorku s vyšší molekulovou hmotností PEG-u. V predložené diplomové práci bylo potvrzeno, že množstvím a molekulovou hmotností polyethylenglykolu je možné rídit hydrolytickou stabilitu výsledných biodegradabilních polyuretanových elastomeru.

Diploma thesis studies the effect of temperature (75 and 105 °C) and the effect of 3 kinds of liquids (silicone and hydraulic oil and coolant) at room temperature and at 105 °C on change of the structure of 3 species butadiene-acrylonitrile (NBR) seals (o-ring and two types of bolts). The seals are inspected by the thermogravimetric analysis, differential scanning calorimetry and infrared spectroscopy, the influence of 105 °C on the o-rings is also evaluated in terms of changes in tensile properties. The greatest changes in the composition and structure are observed on o-rings particularly due to temperature of 105 °C, there was a significant reduction in dilatability and an increase in stiffness and glass transition temperature. The root cause is the surface and centre additive decomposition and oxidation. The bolts have suffered from decomposition of the protective surface layer and the additives in the centre, structural change was minor. Exposure to 75 °C has resulted in a gradual loss of low molecular weight substances. Liquids at room temperature didn‘t affect the structure of the seals, at 105 °C it caused a loss of weight due to decomposition of the protective surface layer and release of additives and the products of their decomposition. Results showed that the common use of the NBR seals at 105 °C is unsuitable, at 75 °C it leads to gradual changes, loss in mechanical and sealing properties.

Title: Microstructure, swelling and deformation behavior of methacrylate hydrogels with interpenetrating network structure Author: Zhansaya Sadakbayeva Department: Department of Macromolecular Physics, Faculty of Mathematics and Physics, Charles University in Prague Supervisor: Ing. Miroslava Dušková-Smrčková, Dr., Institute of Macromolecular Chemistry, Czech Academy of Sciences Consultant: Prof. Ing. Karel Dušek, DrSc., Institute of Macromolecular Chemistry, Czech Academy of Sciences Abstract: This work is devoted to interpenetrating polymer network (IPN) hydrogels prepared by sequential processes of redox-initiated radical polymerization of the first network prepared from 2-hydroxyethyl methacrylate (HEMA), and UV- initiated radical polymerization of the second network prepared from 2-hydroxyethyl methacrylate (HEMA) or glycerol methacrylate (GMA). Microstructure, swelling and deformation responses of the IPN hydrogels and their constituent network hydrogels were tested by various techniques. The microstructure of the first poly(HEMA) network was found sensitive to polymerization conditions. A novel route for one-step synthesis of double-porous poly(HEMA) cryogel was proposed. The formation of the second poly(GMA) network in the environment of non-porous and macroporous poly(HEMA) parent networks was...