Thesis (Ph. D.)--Johann Wolfgang Goethe University, 2003. / Includes bibliographical references.

Orientador: Francisco de Assis Mollo Junior / Banca: João Neudenir Arioli Filho / Banca: Sergio Sualdini Nogueira / Banca: Rafael Leonardo Xediel Consani / Banca: Pedro César Garcia de Oliveira / Resumo: Dentre as inúmeras fases clínicas e laboratoriais de um tratamento protético, as técnicas de moldagem para próteses implantossuportadas são ainda responsáveis por grande preocupação e controvérsia entre os pesquisadores. Este estudo in vitro teve como objetivo avaliar a precisão tridimensional das moldagens para próteses sobre implantes, utilizando-se a técnica direta, variando-se os transferentes (transferentes quadrados, transferentes quadrados com extensão vestíbulo-lingual, transferentes quadrados unidos com Duralay, transferentes quadrados unidos com barra de metal e Index), o tipo de material de moldagem (Impregum Soft média viscosidade, Express consistência regular - 3M ESPE) e a disposição dos implantes (alinhados e não-alinhados). Todos os componentes protéticos utilizados foram da empresa Conexão (Conexão Sistemas de Prótese). Foi construído um modelo mestre de resina epóxica simulando um arco inferior parcialmente desdentado onde foram fixados seis análogos de pilares Micro-Unit. Foi obtido um total de cinqüenta e seis modelos, sendo sete por técnica, mais sete registros do index. Estas medições tridimensionais foram feitas por um programa (ReflexSoft 1.0) que recebia as imagens StereoMicroscópio Reflex. Os valores de distorção médios obtidos foram: Index = 25,88μm (±3,41 SD); Quadrado/ Impregum = 80,22μm (±6,36 SD); Quadrado/ Express = 80,72 μm (±4,92 SD); Quadrado Duralay/Impregum = 84,63 μm (±9,22 SD); Quadrado Duralay/ Express =78,73 μm (±6,84 SD); Quadrado hélice/ Impregum = 30,72 μm (±3,53 SD); Quadrado Hélice/ Express = 30,21 μm (±4,08 SD); Quadrado Barra Metálica/Impregum = 57,08 μm (±5,96 SD); Quadrado Barra Metálica/ Express = 50,77 μm (±4,82 SD). Os testes estatísticos utilizados foram Holm-Sidak Method e Mann-Whitney (a=0,05). Pode-se concluir que em relação às técnicas estudadas que: ...(Resumo completo, cliar acesso eletrônico abaixo) / Abstract: An epoxy resin cast of a partially dentulous mandibular was fabricated with 6 abutment replicas. Nine groups were formed: (Index(I); squared impression copings/ Impregum (SI), metal splinted Impression copings/ Impregum (MI), Duralay splinted impression copings/Impregum (DI), Squared modified Impression copings/ Impregum (SMI), squared impression copings/ Express (SE), metal splinted Impression copings/ Express (ME), Duralay splinted impression copings/ Express (DE) and Squared modified Impression copings/ Express (SME) with 7 casts each were formed,. The measurements were analyzed using software that received the images of a video camera coupled Reflex microscope. Data were analyzed with a 1-way analysis of variance at α <.05, followed by the Holm-Sidak Method and Mann-Whitney test (α <.05). Results. The mean values of abutment/framework interface gaps were: I group 25,88μm (±3,41 SD); SI group 80,22μm (±6,36 SD); SE group 80,71μm (±4,92 SD); MI group 57,07μm (±5,96 SD); ME group 50,76μm (±4,82 SD); DI group 84,63μm (±9,22 SD); DE group 78,73μm (±6,84 SD); HI group 30,71μm (±3,53 SD); HE group 30,21μm (±4,08 SD). No significant difference was detected between I group and HI group, and between I group and HE group (P <.05). Did not exist superiority regarding the impression material. / Doutor

Orientador: Paulo Sérgio Perri de Carvalho / Resumo: A formação de uma interface osseointegrada é mais previsível quando osso denso e saudável está em contato com a superfície do implante no momento da instalação. Porém, a colocação de implantes imediatos após exodontia apresenta inúmeras vantagens, entre elas a preservação da arquitetura óssea e gengival dos processos alveolares, além da diminuição do tempo cirúrgico. A utilização de uma superfície modificada proporciona um maior contato ósseo com o implante; baseado em princípios biológicos. A proposta deste trabalho é avaliar qualitativa e quantitativamente a interface entre osso e os implantes de titânio, jateados por Al2O3 instalados imediatamente após exodontias, em cães. Os implantes foram instalados nos alvéolos de pré-molares mandibulares bilateralmente em quatro cães. Foram instalados quatro implantes para cada animal (4mm de diâmetro e 10mm de comprimento) do Sistema Colosso (Emfils®), sendo dois de cada lado da mandíbula. Os animais foram sacrificados aos 120 dias pós-operatórios. As peças foram desmineralizadas, e os implantes removidos. Três implantes foram perdidos, três fibrointegrados e dez osseointegrados. A análise quantitativa foi realizada considerando-se cinco roscas apicais e o fundo do implante. A análise histológica mostrou tecido ósseo saudável em fase de maturação em íntimo contato com os implantes osseointegrados. Na análise histométrica, observou-se um contato ósseo de 76% nos implantes osseointegrados. / Abstract: An osseointegrated interface could be predictable when dense and healthy bone is in contact with the titanium implant surface at the moment of implant insertion. However, immediate implantation after exodontia presents numerous advantages, among them, maintenance of bone and gingival architecture and decrease of operative time. The use of an implant with modified surface favors bone contact, according to biological principles. This study aims to evaluate the interface between bone and Al2O3 blasted titanium implants installed in 4 dogs immediately after bilateral exodontias of mandibular premolars. Four Emfils® implants (Sistema Colosso - 4mm diameter; 10mm length), 2 per side, were used in each dog. Animals were sacrificed after 120 days of surgery and the samples removed. Bone was decalcified and the implants removed. Three implants were lost, 3 had fibrointegration and 10 osseointegrated. Histological analysis showed a healthy tissue in process of maturation interfacing osseointegrated implants. Quantitative analysis was focused in 5 apical threads and the bottom of the implants. It was shown a contact of 76% between bone and the implants. Osseointegration was achieved around Al2O3 blasted titanium implants installed immediately after exodontias. / Doutor

Orientador: Marcos Rogério de Mendonça / Banca: Osmar Aparecido Cuoghi / Banca: Paulo Cesar Tukasan / Resumo: O objetivo deste estudo foi avaliar a atividade eletromiográfica dos músculos masseter e temporal anterior em crianças com mordida cruzada posterior unilateral funcional. A amostra foi composta por 8 crianças com idade de 5 a 10 anos, um menino e sete meninas que não apresentavam hábitos parafuncionais, sintomas neuromusculares como dor ou fadiga e disfunção temporomandibular. As análises eletromiográficas foram realizadas nestes músculos na posição de repouso, máximo apertamento dentário na posição de máxima intercuspidação e durante a mastigação no lado da mordida cruzada e no lado não cruzado, antes (T1) e após (T2) o tratamento da mordida cruzada posterior unilateral funcional com a utilização do aparelho ortodôntico quadrihélice. Os resultados mostraram uma diferença significante somente para o músculo temporal anterior do lado da mordida cruzada para a posição de repouso, mas houve uma tendência para um aumento no temporal anterior do lado não cruzado e para o masseter do lado cruzado, enquanto houve uma diminuição no masseter do lado não cruzado. Durante o apertamento dentário na posição de máxima intercuspidação, todos os músculos monstraram uma tendência ao aumento da atividade eletromiográfica. Durante a mastigação, houve uma tendência para diminuir a atividade em todos os músculos, exceto para o temporal anterior do lado da mordida cruzada, que registrou um aumento. / Abstract: The purpose of this study was to evaluate the electromyographic activity of masseter and anterior temporal muscles in children with unilateral functional posterior crossbite. The sample was compounded of 8 children aged 5 to 10 years, one boy and seven girls that not present parafunctional habits, neuromuscular symptoms referring to pain or fadigue and temporomandibular disfunction. Electromyographic evaluations were carried out in these muscles at rest position, maximal bite in the intercuspal position and during chewing on the crossbite side and on the noncrossbite side, before (T1) and after (T2) unilateral functional posterior crossbite treatment by using quadhelix orthodontic appliance. The results showed significant difference only for anterior temporal muscle on the crossbite side at rest position, but there was tendency to increase in the anterior temporal on the noncrossbite side and in the masseter on the crossbite side, while there was a decrease in masseter on the noncrossbite side. During maximal bite in the intercuspal position before treatment, all muscles showed a tendency to increase the electromyograpihc activity. During chewing, there was a tendency for decrease activity in all muscles, except for anterior temporal on the crossbite side, that registered an increase. / Mestre

Made available in DSpace on 2015-07-22T20:50:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-11-25 / Objetivo: Análise histomorfométrica de implantes craniofaciais de diâmetros e formatos diferentes com superfície lisa e porosa em tíbia de coelhos. Método: Foram utilizados nessa pesquisa oito coelhos, adultos, fêmeas, albinos, raça Nova Zelândia. Instalamos 40 implantes craniofaciais com formatos cilíndricos (3,75 e 5,0 mm de diâmetro) e cônico (4,3 mm de diâmetro) ambos com 5 mm de comprimento. Os coelhos foram sacrificados 12 semanas, após a instalação dos implantes e as amostras de tecido ósseo submetidos à análise histomorfométrica, para avaliação do contato osso-implante e quantidade de osso formado entre as roscas dos implantes. Resultados: Os valores globais (média e desvio-padrão) do contato osso-implante dos implantes com superfície porosa foi de 73,77% ±6,25 e os implantes com superfície lisa 59,79% ±8,32. Individualmente os valores do contato osso-implante foram os seguintes: o implante poroso de 5,0 mm 72,67% ±7,44, implante liso de 5,0 mm 58,33% ±7,01, implante poroso 4,3 mm 76,80% ±5,58, implante liso 4,3 mm 61,26% ±9,78 e implante poroso 3,75 mm 71,84% ±5,24. Conclusão: existe maior valor estatisticamente significante (p<0,001) de contato osso-implante nos implantes com superfície tratada. Não existe diferença estatisticamente significante, quanto ao contato osso-implante, entre os diferentes tamanhos de implante (3,75 mm / 4,3 mm / 5,0 mm) e formatos dos mesmos (cônico e cilíndrico). / Purpose: Histomorphometric analysis of craniofacial implants of different shapes and diameters, with machined and porous surfaces, placed in the tibia of rabbits. Method: In this study, 40 craniofacial implants with cylindrical shapes (3.75 and 5.0 mm in diameter) and conical (4.3 mm in diameter) both with 5 mm in length were implanted in the tibia of 8 adult female New Zealand white rabbits. The animals were sacrificed 12 weeks after installation of implants. Bone specimens were prepared for histomorphometric assessment of the bone-to-implant contact and the bone volume formation between implant threads. Results: The overall bone-to-implant contact values (mean and standard deviation) were 73.77 ± 6.25% with porous surface implants and 59.79 ± 8.32% with machined surface implants. Individual group values of bone-to-implant contact were as follows: 5.0 mm porous implant 72.67 ± 7.44%; 5.0 mm machined implant 58.33 ± 7.01%; 4.3 mm porous implant 76.80 ± 5.58%; 4.3 mm machined implant 61.26 ± 9.78%; and 3.75 mm porous implant 71.84 ± 5.24%. Conclusion: There was statistically significant greater bone-to-implant contact values with porous surface implants (p <0.001). There was no statistically significant difference on the bone-to-implant contact between different implant sizes (3.75 mm / 4.3 mm / 5.0 mm) and shapes (cylindrical and conical). / TEDE / BV UNIFESP: Teses e dissertações

Resumo: Desde que não há consenso em relação a técnica de moldagem mais precisa, foi objetivo deste estudo in vitro avaliar a precisão de 1 técnica de registro (Index de resina composta) e de 5 técnicas de moldagem para próteses implantossuportadas (transferentes quadrados, quadrados jateados, quadrados com extensão lateral, quadrados unidos com Duralay e quadrados unidos com barra de metal) empregando-se 3 materiais de moldagem: silicone de polimerização por adição consistência densa/fluida com moldeira de estoque de inox, poliéter média viscosidade e silicone de polimerização por adição consistência regular com moldeira individual. Foram construídos 1 modelo mestre com 4 análogos de pilares Micro-Unit e 1 estrutura metálica. Obteve-se do modelo mestre um total de 45 modelos, sendo 5 por técnica. A estrutura metálica foi parafusada utilizando-se a técnica de mensuração de fendas por um parafuso. Estas medições foram feitas com o auxílio do programa Leica QWin que recebeu as imagens de uma câmara de vídeo acoplada a uma lupa com um aumento de 100 x. Os resultados obtidos foram analisados estatisticamente utilizando o teste de Kruskal-Wallis seguido pelo método de Dunn, !=0,05. Dentro das condições experimentais deste estudo, podese concluir que não houve diferença estatística entre: modelo mestre (31,63 !m), quadrado Impregum (38,03 μm), quadrado jateado Impregum (46,80 μm), Index (45,25 μm) e quadrado com extensão lateral Express consistência densa/fluida (51,20 μm), sendo esta a eleita. Devido aos piores resultados obtidos com as técnicas quadrado Express regular (151,21 μm) e quadrado jateado Express regular (136,59 μm), o material de moldagem Express consistência regular não deve ser empregado, sendo escolhido então para ser utilizado com moldeiras individuais o Impregum viscosidade média. Caso o cirurgião-dentista pretenda realizar... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Since there is still no consensus regarding the most accurate impression techniques, it was the purpose of this study compared the dimensional accuracy of stone index and of 5 impression techniques for implant-supported prostheses (squared impression copings, modified squared, !squared sandblasted and coated with impression adhesive, modified squared, Duralay splinted and metal splinted) using 3 impression materials: vinyl polysiloxane putty/light body with a metal stock tray and polyether medium consistency and vinyl polysiloxane regular body were used with a custom aluminum tray. A master cast with 4 parallel implant abutment analogs and a framework were fabricated. Nine groups (n=5) were tested. The gap measurement method employed was just one titanium screw tightened to the framework. Group's measurements were analyzed using LeicaQWin software that received the images of a video camera coupled to a stereomicroscope at x100 magnification. The results were statistically analyzed with Kruskal-Wallis One Way ANOVA on Ranks test followed by Dunn's Method, !=.05. Under the conditions of this study the following conclusions could be drawn: no significant difference was detected among Master Cast (31.63 !m), Squared Impregum (38.03 !m), Sandblasted-Adhesive Squared Impregum (46.80 !m), Index (45.25 μm) and Modified Squared techniques (51.20 μm) (P=.05), being the elected. Due to the worst results with the techniques Squared Express Regular (151.21 μm) and Sandblasted-Adhesive Squared Express Regular (136.59 μm), the Express regular body impression material should not be used, and then chosen to be used Impregum Soft medium consistency with custom tray. If the dentist wishes to perform the technique with splinted copings (Metal Splinted = 68.55 !m and Duralay Splinted = 165.03 !m), the splint should be made with bars of metal. The impression technique using sandblasted-adhesive squared... (Complete abstract click electronic access below) / Orientador: Marco Antonio Compagnoni / Coorientador: Francisco de Assis Mollo Junior / Banca: Wellington Cardoso Bonachela / Banca: Ricardo Faria Ribeiro / Banca: Gelson Luis Adabo / Banca: João Neudenir Arioli Filho / Doutor

Orientador: Ana Paula Rosifini Alves Claro / Coorientador: Maria Cristina Rosifini Alves Rezende / Banca: Carlos Roberto Grandini / Banca: Estevão Tomomitsu Kimpara / Banca: Mônica Beatriz Mathor / Banca: Ana Christina Alves Rezende / Resumo: Os Biomateriais Metálicos são utilizados para reforçar ou para restaurar a forma e função de tecidos duros. Os implantes e próteses são utilizados para substituir ombros, joelhos, quadris e dentes perdidos entre outros. Nos últimos anos, varias ligas de titânio para aplicações biomédicas foram avaliadas. Neste trabalho, a influência do tratamento de superfície biomimético na osseointegração de implantes dentários da liga Ti-7,5Mo foi avaliada. Os lingotes foram obtidos a partir de titânio e molibdênio utilizando um forno a arco voltaico. Eles foram submetidos a tratamento térmico e conformados a frio em prensa rotativa. Posteriormente foram confeccionados implantes (2,0 mm de diâmetro e 2,5 mm de comprimento) sob medida os quais submetidos ao tratamento de superfície biomimético. Os implantes foram inseridos e analisados histológica realizada após 28 dias. A caracterização microestrutural e mecânica da liga Ti-7,5Mo também foi realizada. Aliga Ti-7,5Mo exibiu baixo modulo de elasticidade e elevada relação resistência/modulo. O uso do tratamento de superfície biomimético promoveu um aumento da osseointegração sobre a superfície dos implantes / Abstract: Metallic biomaterials are used to reinforce or to restore form and function of hard tissues. Implants and prosthesis are used to replace shoulders, knees, hips and teeth. In the last years, several titanium alloys for biomedical applications have been studied. In the present work, influence of biomimetic surface treatment in osseointegration of Ti-7.5Mo dental implant was evaluated. Ingots were obtained from titanium and molybdenum by using an arc-melting furnace. They were submitted to heat treatment and cold worked by swaging. Then, screw-shaped implants (2.0 mm diameter by 2.5 mm length) were custom made and they were submitted biomimetic surface treatment. Implants were implanted in the rat's femur and histological analysis was realized after 28 days. Also, microstructural and mechanical properties of Ti-7.5Mo alloy were evaluated. Ti-7.5Mo showed low elasticity modulus and higher ratio strength/modulus. Results obtained suggest that Ti-7.5Mo exhibited excellent bulk properties. The use of the biomimetic surface treatment was able to promote an increase of osseointegration on surface of dental implants / Doutor

Les glucides, les biomolécules les plus abondants dans la nature, sont essentiels pour le maintien et la survie des organismes. Certaines molécules à base de glucides à la fois d'origine synthétique et naturelle sont connues pour leurs activités pharmacologiques et utilisés pour traiter différentes maladies. Deux projets ont été réalisés sur la base d'oligosaccharides biologiquement actifs dans cette thèse. Sialyl Lewis X (sLex), un tétrasaccharide exprimé sur la surface cellulaire d'un tissu embryonnaire et un tissu tumoral, a été découvert pour jouer un rôle important dans l'adhésion entre les cellules tumorales et les cellules endothéliales dans les métastases tumorales à travers la liaison de E-sélectine avec une forte affinité et sélectivité. E-sélectine est un membre de famille des sélectines des molécules d'adhésion cellulaire, exprimée sur l'endothélium tumoral qui est activé par la cytokine. En conséquence, un type de sonde moléculaire basé sur sLex a été conçu et synthétisé dans le but de diagnostiquer le cancer. Aminoéthyle glycoside de sLex 36 a été efficacement préparé à partir de quatre synthons monosaccharidiques par sept étapes d’une manière hautement stéréosélective et régiosélective avec un rendement total de 18%. La sonde moléculaire conjuguant 36 avec une protéine marqué a été montré capable de visualiser une tumeur implantée chez la souris par imagerie in vivo, alors que le contrôle négatif a donné seulement un profil de circulation vasculaire. Ce travail est actuellement dans le processus d'un dépot de brevet. D'autre part, le mécanisme de traitement des N-glycanes par l'endo-α-mannosidase et les inhibiteurs de cette enzyme ont été étudiés. Décorations de N-glycane existent sur la plupart des protéines eucaryotes et leurs compositions aberrantes sont associés à diverses maladies, y compris les infections virales et le cancer. Endo-α-mannosidase hydrolyse la liaison α-1,2-mannosidique entre le mannose en glucose-substitué et le reste de la N-glycane dans l'appareil de Golgi, en fournissant une voie indépendante de glucosidase I et II pour la maturation de N-glycane. Le but de présente étude est de confirmer le mécanisme catalytique nouvellement proposé pour endo-α-mannosidase: la participation du groupe voisin via un 1,2-anhydro intermédiaire de sucre. Etant donné que cet intermédiaire est instable, le glycosyl-1,2-β-anhydro carbasucre 53 a été conçu et synthétisé pour soutenir l'existence de cet intermédiaire pour l'hydrolyse catalysée par glycosidase. De plus, le glycosyl-1,2-β-aziridine carbasucre 64 et le glycosyl-1,2-oléfinique carbasucre 63 ont été conçus et synthétisés comme nouveaux inhibiteurs d’endo-α-mannosidase pour le développement d'agents thérapeutiques. En outre, le glycosyl-1,2-α-anhydro carbasucre 52 et le glycosyl-1,2-α-aziridine carbasucre 65 ont également été synthétisés comme références. Tous les composés cibles ont été préparés de manière efficace à partir du même glycosyl-carbasucre qui a été obtenu de D-(+)-maltose par plusieurs étapes de protections, de modifications, du réarrangement de Claisen. L'évaluation biologique est en cours. / As the most abundant biomolecules found in nature, carbohydrates are essential for sustaining and survival of organisms. Some carbohydrate-based molecules both of synthetic and natural origin are known for their pharmacological activities and used to treat different diseases. Two projects were carried out based on biologically active oligosaccharides in this thesis. Sialyl Lewis X (SLex), which is a tetrasaccharide expressed on cell surface of embryonic tissue and tumor tissue, was discovered to play an important role in the adhesion between tumor cells and blood endothelial cells in tumor metastases through binding E-selectin with high affinity and selectivity. E-selectin is a member of the selectin family of cell adhesion molecules, expressed on cytokine activated tumoral endothelium. Accordingly, a kind of molecular probe based on sLex was designed and synthesized for the purpose of diagnosing cancer. Aminoethyl glycoside of sLex 36 was efficiently prepared from four monosaccharide building blocks through seven steps with high stereoselectivity and regioselectivity in 18% total yield. The molecular probe conjugating 36 with a labelled scaffold protein was shown to visualize an implanted tumor in the mouse by in vivo imaging, whereas the negative control gave only a vascular circulation profile. This work is currently in the process of a patent application. On the other hand, N-linked glycans processing mechanism by endo-α-mannosidase and this enzyme’s inhibitors were studied. N-glycan decorations exist on the majority of eukaryotic proteins and their aberrant compositions are associated with various diseases, including viral infection and cancer. Endo-α-mannosidase hydrolyzes the α-1,2-mannosidic bond between the glucose-substituted mannose and the rest of the N-glycan in Golgi apparatus, providing a glucosidase I and II independent pathway for the maturation of N-glycan. The aim of the present study is to confim the newly proposed catalytic mechanism for endo-α-mannosidase: neighboring group participation via a 1,2-anhydro sugar intermediate. Since this intermediate is unstable, glycosyl-1,2-β-anhydro carbasugar 53 was designed and synthesized to support the existence of this intermediate for glycosidase-catalyzed hydrolysis. Moreover, glycosyl-1,2-β-aziridine carbasugar 64 and glycosyl-1,2-olefinic carbasugar 63 were designed and synthesized as novel endo-α-mannosidase inhibitors for the development of therapeutic agents. In addition, glycosyl-1,2-α-anhydro carbasugar 52 and glycosyl-1,2-α-aziridine carbasugar 65 were also synthesized as compare. All the target compounds were prepared efficiently from the same glycosyl-carbasugar that was obtained from D-(+)-maltose through several steps of protections, modifications, and Claisen rearrangement. The biological evaluation is underway.

Introduction: The aim of this in vitro study was to determine the influence of two glide path preparation methods on the fracture rate of the Primary 25/08 WaveOne reciprocating instrument. The number of simulator Endo-Training-Blocks in each group were calculated at the time of instrument fracture and compared to determine the influence of glide path preparation on the failure rate of the Primary 25/08 WaveOne reciprocating instrument. Preparation times for different glide path methods and total time for root canal preparation, with or without glide path, was also calculated. Materials and Methods: Simulator Endo-Training-Blocks (n = 300) were selected and randomly divided into 3 groups (n = 100). The 3 groups were then sub-divided into 5 smaller groups (n = 20). Root canal preparation was done with new primary 25/08 WaveOne instruments allocated to each group (5 in total for each group, 1 for each sub-group) following different methods for glide path preparation. Group 1: no glide path (control); Group 2: glide path preparation with stainless-steel hand files (size 10 K-File followed by size 15 K-File and finally size 20 K-File until loose fitting); and Group 3: glide path preparation with rotary PathFiles (size 10 K-File until loose fitting followed by PathFile no.1 (ISO 13 tip), PathFile no.2 (ISO 16 tip) and finally PathFile no. 3 (ISO 19 tip)). The Primary 25/08 WaveOne reciprocating instrument was used with the WaveOne endodontic motor in “WaveOne All “mode with a brushing motion on the outstroke. Simulated root canals were irrigated with sterile water and Glyde was used as lubricating agent. The outcome was measured by recording how many simulators could be prepared with one instrument before instrument breakage occurred. The preparation protocol was repeated 5 times. The time it took to prepare the glide path and the total preparation time was also calculated. The data of the different parts of the project were collected and statistically analysed using the ANOVA / Bonferroni test. Results: Glide path preparation with PathFiles was significantly faster (13.3 s ± 2.60 s) than with hand files (25.1 s ± 1.70 s) (P < 0.001). The highest number of simulators could be prepared after glide path preparation was performed with PathFiles (19.2 ± 0.84) (P < 0.001). Pairwise comparisons at the Bonferroni adjusted significance level of 0.017 demonstrated that there were statistical significant differences (P < 0.001) when PathFiles (19.2 ± 0.84) and hand files (17.6 ±1.14) were compared to the no glide path group (7.4 ± 0.89). There was no statistical significant difference between PathFiles and hand files groups. Total Preparation time was significantly shorter (P < 0.001) when an initial glide path was prepared with PathFiles (12.7 ± 0.22 s). The longest preparation time (P < 0.001) was calculated in group 1 where no glide path (21.2 ± 0.20 s) was present and the Endo-Training-Blocks were left undisturbed. Conclusion: Initial glide path preparation with PathFiles resulted in shorter preparation time (glide path and total preparation) and allowed a higher number of simulators prepared before failure of the WaveOne instrument. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Odontology / unrestricted

Bacillus sp VLSH08 screened from sea wetland in Nam Dinh province produces an extracellular endo-1,4-beta-glucanase. According to the results of the classified Kit API 50/CHB as well as sequence of 1500 bp fragment coding for 16S rRNA gene of the Bacillus sp VLSH 08 strain showed that the taxonomical characteristics between the strain VLSH 08 and Bacillus amyloliquefaciene JN999857 are similar of 98%. Culture supernatant of this strain showed optimal cellulase activity at pH 5.8 and 60 Celsius degree and that was enhanced 2.03 times in the presence of 5 mM Co2+. Moreover, the gene encoding endo-1,4-beta-glucanase from this strain was cloned in Escherichia coli using pCR2.1 vector. The entire gene for the enzyme contained a 1500-bp single open reading frame encoding 500 amino acids, including a 29-amino acid signal peptide. The amino acid sequence of this enzyme is very close to that of an EG of Bacillus subtilis (EU022560.1) and an EG of Bacillus amyloliquefaciene (EU022559.1) which all belong to the cellulase family E2. A cocktail of enzyme containing this endo-1,4-beta-glucanase used for biomass hydrolysis indicated that the cellulose conversion attained to 72.76% cellulose after 48 hours. / Chủng vi khuẩn Bacillus sp VLSH08 được tuyển chọn từ tập hợp chủng vi khuẩn phân lập ở vùng ngập mặn tỉnh Nam Định có khả năng sinh tổng hợp enzyme endo-1,4-beta-glucanase ngoại bào. Kết quả phân loại chủng vi khuẩn Bacillus sp VLSH08 bằng Kit hóa sinh API 50/CHB cũng như trình tự gen mã hóa 16S rRNA cho thấy độ tương đồng của chủng Bacillus sp VLSH08 và chủng Bacillus amyloliquefaciene JN999857 đạt 98%. Dịch lên men của chủng được sử dụng làm nguồn enzyme thô để nghiên cứu hoạt độ tối ưu của enzyme ở pH 5,8 và nhiệt đô 60oC. Hoạt tính enzyme tăng 2,03 lần khi có mặt 5 mM ion Co2+. Đồng thời, gen mã hóa cho enzyme endo-1,4-betaglucanase cũng được tách dòng trong tế bào Escherichia coli sử dụng vector pCR 2.1. Gen mã hóa cho enzyme này có chiều dài 1500 bp, mã hóa cho 500 axit amin, bao gồm 29 axit amin của chuỗi peptid tín hiệu. So sánh cho thấy trình tự gen endo-1,4-beta-glucanase của chủng Bacillus sp VLSH08 có độ tương đồng cao với enzyme này của chủng Bacillus subtilis (EU022560.1) và của chủng Bacillus amyloliquefaciene (EU022559.1). Tất cả các enzyme nhóm này đều thuộc họ cellulase E2. Enzyme của chủng này cũng đã được phối trộn với các enzyme khác tạo thành cocktail để thủy phân sinh khối cho kết quả cellulose bị thủy phân 72,76% sau 48 giờ.