O presente trabalho teve como objetivo comparar clinicamente através da taxa de sobrevida e análise de freqüência de ressonância, dois implantes instalados na região anterior da mandíbula, submetidos à carga funcional imediatamente a instalação dos implantes, através de anéis de retenção isolados presos a uma sobredentadura, com um implante instalado na mesma região, livre de carga funcional. Com este objetivo, onze pacientes foram selecionados para instalação de três implantes osteointegráveis em cada, sendo o implante livre de cargas funcionais utilizado como grupo controle. Através dos resultados obtidos, dos vinte e dois implantes submetidos à carga funcional imediata, dois foram perdidos, apresentando uma taxa de sobrevida proporcional a amostra de 93.9%. Quanto ao grupo controle, nenhum implante foi perdido. Após 4 anos de controle clínico, todos os implantes apresentam-se osteointegrados. / The present study aimed to clinically compare through resonance frequency analysis and survival rate, one implant installed in the mandibular anterior region, free from functional load, with two implants installed in the same region, submitted to immediate functional load through isolated retention rings attached to an overdenture. With this purpose, eleven patients were selected for installation of three implants in each. The implants free from functional load were used as the control group. Through the obtained results, two implants of the twenty-two implants submitted to immediate functional load were lost, representing a survival rate of 93.9%. As for the control group, no implants were lost. After 4 years of clinical control all implants remained integrated.

A passividade tem sido descrita como um requisito importante para a longevidade de restaurações implanto-suportadas e, na busca incessante por materiais e técnicas que desempenhem um melhor resultado biomecânico para este tipo restauração, surgem os métodos baseados em desenho e manufatura auxiliados por computador, os chamados métodos CAD/CAM. Assim, o objetivo deste estudo foi comparar o desenvolvimento de tensão provocado pela fixação, por meio do aperto de parafusos, de infraestruturas confeccionadas por duas técnicas CAD/CAM e pela técnica convencional da cera perdida. Para a realização do experimento, foi confeccionado um modelo em poliuretano com dois implantes hexágono externo posicionados nas áreas dos dentes 43 e 45. A partir deste modelo, 12 infraestruturas de três elementos foram fabricadas e divididas em 3 grupos (n=4) de acordo com a técnica utilizada: (C) infraestruturas em Ni-Cr fundidas pela técnica convencional da cera perdida; (U) infraestruturas em zircônia confeccionadas pela técnica CAD/CAM de usinagem e (S) infraestruturas em Co-Cr confeccionadas pela técnica CAD/CAM de sinterização a laser. Durante o aperto dos parafusos para fixação das infraestruturas, as tensões geradas foram registradas por extensômetros unidos aos intermediários e material de osso simulado. De acordo com a técnica utilizada e considerando todos os diferentes locais avaliados, os valores médios de tensão variaram de: 14,28 μξ a 693,40 μξ para o Grupo C; 19,27 μξ a 930,92 μξ para o Grupo U e 5,37 μξ a 196,57 μξ para o Grupo S. Análise de variância a dois critérios para as variáveis técnica de confecção de infraestruturas e local de avaliação da tensão demonstrou que não houve diferença estatisticamente significante entre os valores de tensão em relação à técnica utilizada. Por outro lado, os valores foram significantemente diferentes em relação aos diferentes locais analisados. Desta forma, este estudo concluiu que as duas técnicas CAD/CAM testadas não proporcionaram infraestruturas com passividade superior às obtidas convencionalmente e que todas as peças apresentaram certo grau de desadaptação e consequente falta de homogeneidade na distribuição de tensões pelo sistema. / Passivity property has been described as an important requirement for the longevity of implant-supported restorations. Looking for materials and techniques that provide better biomechanical outcome for such restorations, methods based on design and computer aided manufacturing has emerged, the called CAD/CAM techniques. Therefore, the aim of this study was to compare the strain development during tightening screws on frameworks made from two CAD/CAM techniques and conventional lost wax technique. For the experiment, a polyurethane model with two external hexagon implants, placed at 43 and 45 teeth areas, was made. From this model, 12 three-unit frameworks were produced and divided into 3 groups (n = 4) according to the technique used: (C) Ni-Cr cast frameworks produced by lost wax conventional technique; (U) zirconia frameworks prepared by CAD/CAM milling technique and (S) Co-Cr frameworks prepared by CAD/CAM laser sintering technique. Generated strains, during tightening screws, were recorded by strain gauges attached to abutments and simulated bone material. According to the technique used, which considered, all different sites evaluated, mean strain values ranged from: 14,28 μξ to 693,40 μξ for Group C; 19,27 μξ to 930,92 μξ for Group U and 5,37 μξ to 196.57 μξ for Group S. Two way ANOVA performed for frameworks technique and strain sites demonstrated no statistically significant difference between strain values in relation to the technique used. On the other hand, values were statistically different for distinct sites analyzed. Furthermore, this study concluded that the two CAD/CAM techniques tested did not provide frameworks with better passivity than conventionally obtained ones and that all parts showed some degree of mismatch and consequent lack of homogeneity related to stresses distribution through the system.

O estudo comparativo da distribuição de tensões de von Mises em dente endodonticamente tratado, com dois formatos de retentores intra-radiculares, pré-fabricado cilíndrico/escalonado e fundido cônico, foi realizado pelo método dos elementos finitos em modelos tridimensionais de caninos superiores com geometria axi-simétrica e restaurados com coroas metalocerâmicas, aplicando-se uma carga oblíqua de 100N com 45 º de inclinação em relação ao seu longo eixo. Os resultados indicaram uma discreta diferença nos dois modelos (formatos) de retentores. O pino escalonado neutralizou mais as cargas no sentido corono-apical e no pino cônico ficou evidenciado o efeito de cunha. / The aim of this study was to compare the von Mises stress distribution on a human canine teeth endodontically treated and restored with two types of post and core. The analysis was made using the three dimensional Finite Element Analysis method. For the analysis was created and axy-simetric structure of the teeth, including a porcelain fused to metal crown, a cement layer, and the periodontal structures. The model was analyzed when a 100N load was applied on the surface of the crown with 45º angulation with the long axis of the teeth. The results showed that both models exhibit little difference, the “stair shape” post system neutralized the axial loads, and the conical shape post showed a wedge effect on the apical third of the root.

The thesis is focussed on the reconstruction of a damaged skull represented by a polygonal model. The reconstruction is based on a statistical shape model of the skull. The thesis covers the registration of skulls by using a thin-plate spline method, aligning polygonal models by generalized procrustes analysis, the identification of missing parts of a skull by means of statistical shape models outliers analysis. Finally, missing parts of the skull are reconstructed and the accuracy of the reconstruction is estimated.

Die vorliegende Studie befasste sich mit zwei Fragestellungen. Im ersten Teil wurde die Projektionsabhängigkeit von radiologischen Landmarken im konventionellen Röntgenbild der Schulter und damit deren klinische Anwendbarkeit untersucht. Im zweiten Teil wurde das Auftreten von sog. röntgenhellen Linien (RLL) bei Glenoidersatz im konventionellen Röntgen und im CT untersucht. Beide Fragestelllungen sind in der Beurteilung von Landmarken von Glenoidkomponenten in der Endoprothetik der Schulter von Bedeutung. Zur Beantwortung der ersten Frage wurden 6 mit Markierungen versehene humane Scapula-Leichenpräparate in 25 Projektionen geröntgt und der Einfluss der Projektionen auf gängige Landmarken gemessen. Die Landmarken wurden an der Margo lateralis, Margo medialis, knöchernen Glenoid, Coracoidbasis, Fossa supraspinata und oberen Linie der Spina scapulae festgelegt. Zur Beantwortung der zweiten Frage wurden 10 humane Glenoid-Leichenpräparate mit einzementierter Glenoidkomponente im konventionellen Röntgen und im CT untersucht. Alle gewonnenen radiologischen Bilder wurden von zwei Untersuchern vermessen und die Interobserverreliabilität errechnet. Die Ergebnisse des ersten Teiles sowohl der Messwerte der Landmarken als auch der Interobserverreliabilität zeigten, dass die Margo medialis des Schulterblattes die zuverlässigsten Ergebnisse bei der Robustheit gegen Verkippung zur Beurteilung des Kunststoff Glenoids aufwiesen. Im klinischen Alltag ist diese Landmarke jedoch auf vielen Röntgenbildern der Schulter nicht mit abgebildet. Es zeigte sich, dass die am wenigsten projektionsabhängige Landmarke, die regelmässig auf Schulteraufnahmen abgebildet ist, die Margo lateralis scapulae ist. Als Ergebnis des zweiten Teiles zeigte sich, dass im konventionellen Röntgen sichtbare RLL im CT nicht alle zur Darstellung kamen und somit als Artefakte zu werten waren. Aufgrund der klinisch schwierig durchzuführenden Röntgentechnik kann nicht immer eine exakte AP Aufnahme im konventionellen Röntgen gewonnen werden, wodurch auch projektionsbedingt Doppellinien erscheinen können. Diese wurden vermutlich durch die konvexe Form des PE Glenoids und Zementfehlern verursacht. Zur Beurteilung einer Lockerung sollte also eine Computertomografie angefertigt werden. Weiterhin zeigte sich aber auch im CT, dass frisch implantierte Glenoidkomponenten trotz optimaler Bedingungen RLL aufweisen. Dies zeigte deutlich, dass die Zementiertechnik auch in ihrer modernen Form noch nicht voll ausgereift war und deshalb weiterhin nach Verbesserungsmöglichkeiten gesucht werden sollte. / The aim of this study was to evaluate the reliability of different bony landmarks on radiographs after implantation of a total shoulder arthroplasty when the scapula is tilted compared with the ideal ap view. To assess loosening of the glenoid component, serial evaluation of ap radiographs of the scapula has been established as the 'gold standard. This study also verified the incidence of radiolucent lines (RLL) in radiographs and on CTscans to show different measurements of localization and appearance of the RLL. For the first aim of this study glenoid components were implanted into 6 human cadaveric scapulae. Radiographs were taken exactly anterior-posterior in the frontal plane, as well as craniocaudal tilted (±15° and ±30°) and mediolateral tilted (±10° and ±20°). The following landmarks were evaluated: lateral margin of the scapula, medial margin of the scapula, floor of the fossa supraspinatus line, spine of the scapula line, glenoid fossa line, and coracoid base line. In the second part of this study, 10 glenoid components were implanted into human cadaveric glenoids and a CT-scan as well as radiographs were made in an exact anteriorposterior view. The images were compared to evaluate the localization, incidence and form of the RLL. Every X-ray was measured by two different examiners to show the interobserver reliability. Regarding robustness against glenoid tilt, the medial margin of the scapula had the best intraobserver and interobserver reliability, whereas the lateral margin of the scapula had an acceptable intraobserver and interobserver reliability. In measuring medial migration, the glenoid fossa line had a significantly lower intraobserver and interobserver reliability than the coracoid base line. Because conventional radiographs were hardly done in exact ap direction despite the laboratory within, RLL were seen on X-ray although no RLL actually existed. The CT-scans highlighted the existence of artefacts, which looked like RLL on conventional radiography. The curved form of the glenoid component can cause double lines, which look like RLL on X-rays. However, the conventional radiography can still be used to detect an increase of RLL in postoperativ control X-rays. To be absolutely sure whether RLL do exist a CT-scan has to be done. This study shows that, even under best conditions for an implantation of glenoid components RLL can be viewed due to false cementation technique. The results underline that the cement implantation can still be improved to minimize the incidence of RLL.

Syfte Syftet med föreliggande studie är att genom en systematisk översikt identifiera skillnaderna i de kemiska och mekaniska egenskaperna hos materialen PEEK och PEKK och till vilka dentala applikationer materialen kan användas.  Material och metod Materialens kemiska och mekaniska egenskaper identifierades genom litteratursökning med PRISMA och PICO-systemet. Databaserna som användes var PubMed, Scopus samt Web of Science. Granskning gjordes på titel-, abstrakt- och fulltextnivå, baserat på inklusions- och exklusionskriterier. Resultat Sökningen resulterade i totalt 226 artiklar varav 210 artiklar i PubMed, nio artiklar i Scopus och sju artiklar i Web of Science. Efter kontroll av dubbletter och bedömning utifrån inklusions- och exklusionskriterier var det totalt sju artiklar som analyserades på fulltextnivå. Av dessa sju artiklarna utvärderades olika materialegenskaper där de använda materialtesterna skiljde sig åt. I fem artiklar utvärderades bindningsstyrkan mellan fasadmaterial och PEEK och/eller PEKK. En artikel undersökte ytan hos materialen beroende på ytbehandling och en artikel testade tryckhållfasthet på tre-ledsbroar av PEEK och PEKK. Båda materialen uppvisade liknande mekaniska och kemiska egenskaper vid jämförelse mot varandra.  Slutsats PEEK och PEKKs mekaniska och kemiska egenskaper skiljer sig inte åt. Mer forskning och kliniska data behövs om materialens dentala applikationer. Nyckelord: Avtagbar protetik, fast protetik, högpresterande polymer, PAEK, tandvård / Purpose The purpose of the present study is to carry out a systematic review to identify the differences in mechanical and chemical properties of the materials PEEK and PEKK, as well as which  dental applications the materials can be used for.  Material and method The materials’ mechanical and chemical properties were identified using PRISMA and PICO system through a literature search. The databases used were PubMed, Scopus and Web of Science. Screening and assessing were done at title, abstract and full text level, based on the inclusion and exclusion criteria. Results The search resulted in a total of 226 articles, whereon 210 articles in PubMed, nine articles in Scopus and seven articles in Web of Science. After removal of duplicates and assessment of the studies according to the inclusion and exclusion criteria, the total amount of studies reviewed was seven. In these seven articles, different properties were evaluated, and the tests used differed. In five articles, the shear bond strength between veneering materials and PEEK and/or PEKK was tested. In one article the surface roughness depending on surface treatment was tested and in another, the strength of three-unit fixed dental prostheses made of PEEK and PEKK was tested. PEEK and PEKK showed similar mechanical and chemical properties in comparison to each other.  Conclusion The mechanical and chemical properties of PEEK and PEKK do not differ. More research and clinical data are needed on the dental applications of the materials.Keywords: Dentistry, fixed dental prosthesis, high-performance polymer, removable dental prothesis, PAEK.

Introdução: O recente aperfeiçoamento da ultra-sonografia permitiu a análise estrutural e funcional do vaso. Casuística e Métodos: 36 pacientes com insuficiência aórtica e indicação de troca valvar, divididos em grupos com pressão arterial diastólica (PAD) superior e inferior a 50mmHg, avaliados antes e seis meses após a cirurgia. A função arterial compreendeu a complacência, distensibilidade e a função endotelial pela dilatação fluxo-mediada e nitrato-mediada. Conclusão: A complacência e a distensibilidade foram maiores no grupo com menor PAD e diminuíram após a cirurgia. A disfunção endotelial foi presente em insuficiência aórtica crônica independente do nível da pressão arterial diastólica / Introduction: The recent improvement of ultrasonography made possible a functional and structural analysis of the vessel. Methods: 36 patients with aortic insufficiency and valve replacement need, divided in 2 groups with diastolic blood pressure (DBP) above and below 50mmHg. Checked twice: before and 6 months after surgery. The arterial function comprised compliance, distensibility and endothelial function through flow-mediated dilatation and nitrate-mediated dilatation. Conclusion: The compliance and distensibility were higher in the group with lower DBP and decreased after surgery. Endothelial dysfunction was present in chronic aortic insufficiency no matter the level of DBP

Introdução: O recente aperfeiçoamento da ultra-sonografia permitiu a análise estrutural e funcional do vaso. Casuística e Métodos: 36 pacientes com insuficiência aórtica e indicação de troca valvar, divididos em grupos com pressão arterial diastólica (PAD) superior e inferior a 50mmHg, avaliados antes e seis meses após a cirurgia. A função arterial compreendeu a complacência, distensibilidade e a função endotelial pela dilatação fluxo-mediada e nitrato-mediada. Conclusão: A complacência e a distensibilidade foram maiores no grupo com menor PAD e diminuíram após a cirurgia. A disfunção endotelial foi presente em insuficiência aórtica crônica independente do nível da pressão arterial diastólica / Introduction: The recent improvement of ultrasonography made possible a functional and structural analysis of the vessel. Methods: 36 patients with aortic insufficiency and valve replacement need, divided in 2 groups with diastolic blood pressure (DBP) above and below 50mmHg. Checked twice: before and 6 months after surgery. The arterial function comprised compliance, distensibility and endothelial function through flow-mediated dilatation and nitrate-mediated dilatation. Conclusion: The compliance and distensibility were higher in the group with lower DBP and decreased after surgery. Endothelial dysfunction was present in chronic aortic insufficiency no matter the level of DBP