The selection of suitable materials for the renovation of sliding shafts requires a comparison of several criteria. The main criteria were selected size shear strength under tensile stress lap bonded assemblies, resistance to adhesive wear and economic criteria. From the results of all tests is selected the most suitable friction material to repair worn out places of shaft. The technological process of sealing the shaft was drawn up on the basis of the literature, recommendations supplier of sliding materials and their own experience.

The purpose of this study was to evaluate the physical properties of dental sealant resins under aging conditions to determine the critical factors controlling functional property loss with time. The effect of processing on the chemical and thermal properties of several different sealant formulations was evaluated. These processing parameters included the blue light exposure time for each light-curing system and time after illumination. The results indicate that the level of cure for each system was incomplete at the end of all processing procedures. Heating as well as further aging of the cured resin advanced the cure. Additionally, one of our goal was to model the curing characteristics of the sealant as a function of depth in the fissure to evaluate the thickness influence on the sealant mechanical properties. The strength and stiffness of the light-cured sealant varied as a function of depth in the fissure. This results in a gradient of deformation which could cause early fracture of the resin upon chewing. Incomplete resin conversion is important since dental adhesives have been shown to be leached by saliva and the elution products have been recently shown to be potentially estrogenic. Samples of differently processed commercial sealants were immersed in an ethanol/water solution and extractions were analyzed by HPLC. An inverse correlation between the degree of cure and the % of elution as well as high level of extraction was found. An <i>in vivo</i> study has been performed on fifteen pigs. The purpose of the experiment is to obtain data on <i>in vivo</i> sealing ability of the sealant. Low sealant retention rates have been found but interesting observations of sealed fissures were made and the pig can be considered like an acceptable model. / Master of Science

Este estudo avaliou e comparou, após 6 meses, dois materiais usados como selantes de fossas e fissuras, FluroShield® (Dentsply, Germany) e Clinpro&#x2122; XT Varnish (3M ESPE, Dental Products, St. Paul, MN, U.S.A.) quanto à retenção e características superficiais. Além disso, comparou-os, com um grupo controle não selado, com relação à incidência de cárie no período. Participaram deste trabalho, 31 crianças de 6 a 8 anos de idade, com no mínimo dois primeiros molares permanentes hígidos e história de cárie, num total de 114 dentes divididos aleatoriamente em três grupos: CLP (Clinpro&#x2122; XT Varnish), FS (FluroShield®) e ctr (Controle). O selamento foi realizado sob isolamento relativo para ambos os materiais testados, após profilaxia prévia com jato de bicarbonato de sódio e água e, condicionamento com gel de ácido fosfórico a 35% por 15 segundos. A avaliação clínica foi realizada por dois examinadores calibrados após 6 meses. Avaliou-se a retenção e a incidência de cárie nas cinco áreas oclusais: OM, OC, OD, OV e OL; e as características superficiais e a retenção considerando a superfície oclusal como um todo. Houve diferença estatisticamente significante para a prevalência de cárie (teste de Kruskal Wallis, p=0,000 a 0,007), para todas as áreas, entre os grupos selados (CLP e FS) e o controle. Sendo que quanto à incidência, só foi verificada diferença significante para a área OL (p=0,014). O teste do Qui-quadrado identificou que não houve diferença estatisticamente significante entre os materiais, com relação à taxa de sucesso de retenção da superfície oclusal como um todo, quando se considerou o somatório das cinco áreas (p=0,079) ou quando se verificou a retenção por superfície (p=0,141). No entanto, a análise do conjunto de critérios de retenção na superfície oclusal toda, mostrou uma diferença estatisticamente significante para o FS (teste de Mann-Whitney, p=0,002). Em relação às características superficiais, o FS apresentou superioridade durante o período estudado de forma significativa, indicada pelo teste de Mann-Whitney, para a deterioração marginal (p=0,000), descoloração marginal (p=0,008), e descoloração superficial (p=0,001). Ele também foi superior, mas não significante, quanto à textura superficial. A frequência de bolhas nas superfícies seladas não mostrou diferença significativa (teste do Qui-quadrado, p=0,758) entre os materiais. Desta forma, pode-se concluir que ambos os materiais foram efetivos nos primeiros 6 meses de avaliação, embora, tenha havido melhor desempenho clínico do selante FluroShield®. / This study evaluated and compared two dental sealants, for 6 months. The materials, Fluroshield® (Dentsply, Germany) and Clinpro&#x2122; XT Varnish (3M ESPE Dental Products, St. Paul, MN, USA) were analyzed with regard their retention and superficial characteristics. They also were compared with a control group, without sealant, regarding the dental caries incidence. The sample was composed by 31 children from 6 to 8 years of age, with at least two sound first permanent molars, but with a dental caries history. A total of 114 teeth were randomly alocated in three groups: CLP (Clinpro&#x2122; XT Varnish), FS (Fluroshield®) and ctr (Control). The sealings were applyed under relative isolation after a previous prophylaxis with a water-air-polishing jet, and an enamel etching with a 35% phosphoric acid gel for 15 seconds. Clinical evaluation was performed by two calibrated examiners after 6 months considering: the sealant retention and the incidence of occlusal caries in five areas: OM, OC, OD, OV and OL and finally, the surface characteristics and retention considering the occlusal surface as only one area. It was shown a significant difference (Kruskal-Wallis test, p=0.000 to 0.007) for the caries prevalence in all areas comparing the sealed group (CLP and FS) versus control. Whereas the incidence, it was only verified a significant diference for the OL area (p=0.014). There was no significant difference (Chi-square test, p=0.079) between the materials regarding the success rate of retention for the occlusal surface when it was considered the sum of the five areas, or for the occlusal surface without divisions (p=0.141). Nevertheless there was a significant difference between the sealants (Mann-Whitney test, p=0.002), with better results for the FS group, when it was analysed the influence of all the retention criteria. Regarding the surface characteristics, the FS group showed a significant superiority (Mann-Whitney test) during the period of the study for the impairment marginal (p=0.000), marginal discoloration (p=0.008), and surface discoloration (p=0.001). Although FS had also been superior for the surface texture, this result was not significant. The frequency of bubbles in the sealed surfaces was not significant (Qui-square test, p=0.758) between the materials. Thus, it can be concluded that both materials were effective during this first 6 months of evaluation, although it is evident that the Fluroshield® sealant had shown a better clinical performance.

Este estudo avaliou e comparou, após 6 meses, dois materiais usados como selantes de fossas e fissuras, FluroShield® (Dentsply, Germany) e Clinpro&#x2122; XT Varnish (3M ESPE, Dental Products, St. Paul, MN, U.S.A.) quanto à retenção e características superficiais. Além disso, comparou-os, com um grupo controle não selado, com relação à incidência de cárie no período. Participaram deste trabalho, 31 crianças de 6 a 8 anos de idade, com no mínimo dois primeiros molares permanentes hígidos e história de cárie, num total de 114 dentes divididos aleatoriamente em três grupos: CLP (Clinpro&#x2122; XT Varnish), FS (FluroShield®) e ctr (Controle). O selamento foi realizado sob isolamento relativo para ambos os materiais testados, após profilaxia prévia com jato de bicarbonato de sódio e água e, condicionamento com gel de ácido fosfórico a 35% por 15 segundos. A avaliação clínica foi realizada por dois examinadores calibrados após 6 meses. Avaliou-se a retenção e a incidência de cárie nas cinco áreas oclusais: OM, OC, OD, OV e OL; e as características superficiais e a retenção considerando a superfície oclusal como um todo. Houve diferença estatisticamente significante para a prevalência de cárie (teste de Kruskal Wallis, p=0,000 a 0,007), para todas as áreas, entre os grupos selados (CLP e FS) e o controle. Sendo que quanto à incidência, só foi verificada diferença significante para a área OL (p=0,014). O teste do Qui-quadrado identificou que não houve diferença estatisticamente significante entre os materiais, com relação à taxa de sucesso de retenção da superfície oclusal como um todo, quando se considerou o somatório das cinco áreas (p=0,079) ou quando se verificou a retenção por superfície (p=0,141). No entanto, a análise do conjunto de critérios de retenção na superfície oclusal toda, mostrou uma diferença estatisticamente significante para o FS (teste de Mann-Whitney, p=0,002). Em relação às características superficiais, o FS apresentou superioridade durante o período estudado de forma significativa, indicada pelo teste de Mann-Whitney, para a deterioração marginal (p=0,000), descoloração marginal (p=0,008), e descoloração superficial (p=0,001). Ele também foi superior, mas não significante, quanto à textura superficial. A frequência de bolhas nas superfícies seladas não mostrou diferença significativa (teste do Qui-quadrado, p=0,758) entre os materiais. Desta forma, pode-se concluir que ambos os materiais foram efetivos nos primeiros 6 meses de avaliação, embora, tenha havido melhor desempenho clínico do selante FluroShield®. / This study evaluated and compared two dental sealants, for 6 months. The materials, Fluroshield® (Dentsply, Germany) and Clinpro&#x2122; XT Varnish (3M ESPE Dental Products, St. Paul, MN, USA) were analyzed with regard their retention and superficial characteristics. They also were compared with a control group, without sealant, regarding the dental caries incidence. The sample was composed by 31 children from 6 to 8 years of age, with at least two sound first permanent molars, but with a dental caries history. A total of 114 teeth were randomly alocated in three groups: CLP (Clinpro&#x2122; XT Varnish), FS (Fluroshield®) and ctr (Control). The sealings were applyed under relative isolation after a previous prophylaxis with a water-air-polishing jet, and an enamel etching with a 35% phosphoric acid gel for 15 seconds. Clinical evaluation was performed by two calibrated examiners after 6 months considering: the sealant retention and the incidence of occlusal caries in five areas: OM, OC, OD, OV and OL and finally, the surface characteristics and retention considering the occlusal surface as only one area. It was shown a significant difference (Kruskal-Wallis test, p=0.000 to 0.007) for the caries prevalence in all areas comparing the sealed group (CLP and FS) versus control. Whereas the incidence, it was only verified a significant diference for the OL area (p=0.014). There was no significant difference (Chi-square test, p=0.079) between the materials regarding the success rate of retention for the occlusal surface when it was considered the sum of the five areas, or for the occlusal surface without divisions (p=0.141). Nevertheless there was a significant difference between the sealants (Mann-Whitney test, p=0.002), with better results for the FS group, when it was analysed the influence of all the retention criteria. Regarding the surface characteristics, the FS group showed a significant superiority (Mann-Whitney test) during the period of the study for the impairment marginal (p=0.000), marginal discoloration (p=0.008), and surface discoloration (p=0.001). Although FS had also been superior for the surface texture, this result was not significant. The frequency of bubbles in the sealed surfaces was not significant (Qui-square test, p=0.758) between the materials. Thus, it can be concluded that both materials were effective during this first 6 months of evaluation, although it is evident that the Fluroshield® sealant had shown a better clinical performance.

Die flexible Anpassungsfähigkeit an Umgebungsbedingungen und äußere Einwirkungen ist der Schlüssel zur weiteren energetischen Optimierung der Gebäudehülle. Bisherige Glasfassaden mit statischem Eigenschaftsprofil können auf tages- und jahreszeitliche Änderungen von solarer Einstrahlung oder Temperaturverläufen nur unzureichend reagieren. Dynamische Verglasungen gewinnen daher im Fassadenbau immer stärker an Bedeutung. Neben bereits etablierten Systemen wie elektrochromen Gläsern werden in aktuellen Forschungs- und Entwicklungsvorhaben diverse Konzepte für adaptive, multifunktionale Gebäudehüllen untersucht. Einen innovativen Ansatz bildet der Einsatz von Flüssigkeiten im Scheibenzwischenraum von Mehrscheiben-Isolierverglasungen. Diese können thermisch reguliert, mit speziellen Partikeln versetzt oder sogar zur Algenkultivierung verwendet werden und ebnen so den Weg für den Bau von Niedrigstenergiegebäuden. Neben Problemstellungen zur Bauphysik und Gebäudeautomation ergibt sich insbesondere bei der Verbindungstechnik für die einzelnen Glasscheiben aufgrund der direkten Flüssigkeitsexposition ein erheblicher Forschungsbedarf. In ersten, bereits realisierten Pilotprojekten wird der aus der Flüssigkeit resultierende hohe hydrostatische Druck, der auf die Verglasung und damit auch auf den Randverbund wirkt, durch aufgesetzte Klemmleisten abgetragen. Die mechanische Klemmung stellt sicher, dass die Randabdichtung in der Lage ist, ihre Funktion dauerhaft zu erfüllen. Diese aufgesetzte Haltekonstruktion durchbricht jedoch die ebenen Oberflächen, die den Reiz schlanker Glasfassaden ausmachen. Der hohe gestalterische Anspruch, der bei großen Bauprojekten von Architekten und Bauherren nachgefragt wird, kann nur mit einem strukturell geklebten Randverbundsystem erfüllt werden, das für den Einsatz im flüssigen Medium geeignet ist. Bisher sind keine geeigneten Klebverbindungen bekannt, die eine dauerhafte Dichtigkeit und ständigen Abtrag hoher mechanischer Lasten gleichzeitig gewährleisten können. Ein wesentlicher Grund dafür ist, dass aus der eindiffundierenden Feuchtigkeit ein wesentlicher Schädigungsmechanismus für die geklebte Verbindung resultiert. Die Klebstoffsteifigkeit nimmt dadurch in der Regel ab; auch ein Haftverlust kann die Folge sein. Die vorliegende Arbeit stellt sich der beschriebenen Herausforderung einer strukturellen Klebverbindung unter Einfluss einer dauerhaften Flüssigkeitsexposition. Durch ein zweistufig geklebtes Randverbundsystem sollen die wesentlichen Funktionen Dichten und Lastabtragen spezifisch auf separat wirksame Klebstoffe aufgeteilt werden und dadurch ein wesentlicher Vorteil gegenüber bisherigen Klebverbindungen geschaffen werden. Ausgehend von diesem Lösungsansatz werden für die Klebstoffauswahl und Materialcharakterisierung ein umfangreiches, maßgeschneidertes Versuchsprogramm sowie Bewertungskonzept entwickelt. Standardisierte Substanz- und Verbundprüfungen umfassen Zug- und Haft-Zugversuche sowie Versuche zur Materialverträglichkeit. In Anbetracht der speziellen Anforderungen der geplanten Anwendung lassen bis dato existierende Bewertungsgrundlagen und Nachweisverfahren jedoch keine hinreichend zuverlässige Aussage zu. Deshalb werden in dieser Arbeit speziell auf diese Anwendung abgestimmte Versuchsverfahren entwickelt, mit denen die Klebstoffdichtigkeit und Flüssigkeitsaufnahme sowie das Verhalten unter Dauerbeanspruchung analysiert werden. Basierend auf den gewonnenen Ergebnissen werden zwei geeignete Klebstoffsysteme ausgewählt, jeweils eines für die dichtende und eines für die lastabtragende Klebstufe. Weitere experimentelle Versuche fokussieren sich auf die Überprüfung der Funktionalität des neuartigen Randverbundsystems unter Realbedingungen. Mit diesem Ziel wird ein Bauteilprüfstand entwickelt, der die realitätsnahe Prüfung des komplexen Beanspruchungszustands im Randverbundsystem erlaubt. Die Versuche im Bauteilmaßstab 1:2 liefern die notwendige Datengrundlage zur Validierung eines numerischen Berechnungsmodells. Mithilfe des Modells werden der Glasaufbau und das neuartige Randverbundsystem dimensioniert und nachgewiesen. Die gewählte Abstraktionstiefe des Modells ermöglicht dabei sowohl eine wissenschaftlich präzise Beurteilung des Tragverhaltens als auch eine praxistaugliche Bemessung. Im Ergebnis zeigt sich, dass die Kombination der ausgewählten Klebstoffe eine ausreichende Dichtigkeit und Tragfähigkeit aufweist. Experimentell ermittelte, zeitabhängige Verformungen erlauben eine positive Prognose der zu erwartenden Standzeit. In den Bauteilversuchen bleibt der entwickelte Randverbund selbst im teilzerstörten Zustand der Verglasungen und daraus resultierenden, sehr großen Verformungen intakt. Die Klebfuge wird auch unter gemeinhin kritischen Dauerlasten auf hohem Lastniveau rechnerisch nachgewiesen werden, wenngleich dann die Elementabmessungen gegenüber der ursprünglich angestrebten Elementgröße reduziert werden müssen. Die Ergebnisse der vorliegenden Arbeit zeigen, dass die Umsetzung eines zweistufig geklebten Randverbundsystems für den Einsatz in flüssigkeitsgefüllten Isolierverglasungen möglich ist. Die entwickelten Prüfverfahren mit definierten Beurteilungsmethoden sowie das ausgearbeitete Versuchsprogramm können für ähnlich gelagerte Fragestellungen herangezogen werden.:1 Einleitung 2 Grundlagen 3 Beispielkonstruktion und Beanspruchungsanalyse 4 Klebstoffauswahl und Charakterisierung 5 Anwendungsspezifische Klebstoffuntersuchungen 6 Untersuchungen im Bauteilmaßstab 7 Berechnung und Dimensionierung 8 Handlungsempfehlungenn 9 Zusammenfassung und Ausblick 10 Literatur / Flexible adaptability to environmental conditions and external influences is a key to further energy optimisation of the building envelope. Current glass façades with a fixed characteristics cannot respond adequately to changes in solar radiation or temperature during the day and over the seasons. Dynamic glazing is therefore becoming increasingly important in façade construction. In addition to established solutions such as electrochromic glazing, research and development activities are currently investigating various concepts for adaptive, multifunctional building envelopes. One innovative approach is the use of fluids in the cavity between the panes of insulating glass units. The fluid can be thermally regulated, mixed with functional particles or even used to cultivate algae. This paves the way for the design of ultra-low energy buildings. In parallel with the building physics and automation issues, there is a particular need for research into the connection techniques for the individual panes due to the direct contact with a fluid. In the first completed pilot projects, the high hydrostatic pressure acting on the glazing and therefore also on the edge seal, is dissipated by means of attached clamping bars. These external mechanical clamps ensure that the edge seal is able to fulfil its function permanently. However, external mechanical clamps disrupt the smooth surfaces that define the visual appearance of slim glass façades. This high design requirement, often demanded by architects and clients on high value projects, can only be met by a structurally bonded edge seal system designed for use in a fluid medium. To date, there are no suitable adhesive bonds that can provide both a permanent seal and the ability to withstand high mechanical loads. One of the main reasons for this is the diffusion of moisture, which causes significant damage to the bond. Moisture generally reduces the stiffness of the adhesive and can also cause a loss of adhesion. The present work addresses the challenge of a structural adhesive connection that is permanently exposed to a fluid. By using a two-stage bonded edge seal system, the main functions of sealing and structural load transfer are specifically allocated to the separate adhesives. This results in a significant improvement over conventional bonded joints. Based on this approach, a comprehensive test programme and evaluation scheme is developed to select and characterise the adhesives. Standardised material and adhesive bonding tests include tensile, adhesion and material compatibility tests. Given the specific requirements of the proposed application, conventional evaluation principles and design methods do not provide sufficient assurance. Therefore, this thesis deals with the development of customised test procedures to analyse the adhesive permeability and fluid absorption as well as the structural behaviour under permanent load. Based on the results obtained, two suitable adhesives are selected, one for sealing and one for structural load transfer. Further experimental investigations are focusing on testing the functionality of the novel bonded edge seal system under realistic operating conditions. This includes the development of a component test rig that allows the structural behaviour to be realistically investigated under complex loading conditions. Tests on a 1:2 component scale provide a comprehensive data base for the validation of a numerical model. Numerical simulations are used to dimension and verify the glass composition and the adhesive joint. The high level of detail in the numerical modelling allows a scientifically accurate assessment of the load-bearing behaviour as well as a practical design. The results show that the combination of the selected adhesives provides permanent seal and excellent load carrying capacity. The experimentally determined time-dependent deformations allow for a positive prediction of the service life. Even when the glazing is partially destroyed and the resulting deformations are very large, the developed edge seal remains fully intact during the component tests. The adhesive joint is verified by calculations under generally critical permanent loads at a high stress level, even though the unit dimensions have to be reduced from the original target size. This study demonstrates the feasibility of utilising a two-stage bonded edge seal system in fluid-filled insulating glass units. The customised test methods consisting of specified assessment procedures and an elaborated test programme can be applied to address and overcome forthcoming challenges.:1 Einleitung 2 Grundlagen 3 Beispielkonstruktion und Beanspruchungsanalyse 4 Klebstoffauswahl und Charakterisierung 5 Anwendungsspezifische Klebstoffuntersuchungen 6 Untersuchungen im Bauteilmaßstab 7 Berechnung und Dimensionierung 8 Handlungsempfehlungenn 9 Zusammenfassung und Ausblick 10 Literatur

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / A split-mouth, double-blind trial evaluated the effects of a surface sealant on the clinical performance of Class I composite resin restorations. In 16 patients, 27 pairs of maxillary and mandibular molars or premolars with Class I carious lesions or unsatisfactory restorations were restored with composite resin. For each pair, 1 surface was sealed with surface sealant. Clinical evaluations of marginal integrity, marginal discoloration, anatomical form, and secondary caries were performed by 2 experienced operators using modified US Public Health Service criteria 1-2 weeks and 6 and 12 months after treatment. Data were analyzed with the McNemar test (P < 0.05). After 6 months, only 1 (4%) sealed restoration presented a Bravo rating for marginal integrity. After 12 months, the Bravo ratings for marginal integrity were 2 (7%) for sealed restorations and 1 (4%) for nonsealed restorations. Restorations received a score of Alfa for all other parameters at all time periods. There were no statistically significant differences within or between the sealed and nonsealed groups (P = 1.0). The use of a surface sealant did not improve the clinical performance of posterior composite resin Class I restorations. / Revisión por pares

Este estudo avaliou, in vitro, a influência da aplicação de quatro selantes de superfície na rugosidade de duas resinas compostas. Cinqüenta espécimes foram confeccionados e divididos em 10 grupos com 5 espécimes cada, em função da combinação entre resina composta e selante de superfície, sendo: G1. Controle Concept; G2. Concept + Fortify; G3. Concept + Biscover; G4. Concept + Lasting Touch; G5. Concept + Fill Glaze; G6. Controle Esthet X; G7. Esthet X + Fortify; G8. Esthet X + Biscover; G9. Esthet X + Lasting Touch; G10. Esthet X + Fill Glaze. Os espécimes foram confeccionados com uma matriz específica, em quatro incrementos, com dimensões internas de 15mmX4mmX5mm, sendo sua polimerização realizada com o aparelho de lâmpada halógena Curing Light 2500 (500mW/cm2) por 20s cada incremento. Em seguida, foram armazenados em água destilada à 37ºC e umidade absoluta de 100% por 24 horas. Após este período, os espécimes foram adaptados em uma Politriz Metalográfica e planificados com lixas de granulometria 320, 600 e a rugosidade inicial foi aferida. Para a mensuração da rugosidade, utilizou-se o rugosímetro Hommel Tester T1000 basic. Numa segunda fase, aplicaram-se os selantes de superfície, conforme recomendações do fabricante, e uma nova aferição da rugosidade superficial foi realizada. Para o teste de abrasão, os espécimes foram submetidos a 100.000 ciclos de escovação, seguido de nova mensuração da rugosidade. Em adição à rugosidade e com o objetivo de avaliar qualitativamente a superfície de alguns espécimes, a leitura em Microscopia Eletrônica de Varredura foi empregada. Os resultados foram submetidos aos testes ANOVA a 3 critérios e Tukey para comparações individuais entre os diferentes grupos (p<0,05). A aplicação do selante de superfície diminuiu a rugosidade superficial das resinas compostas testadas (G2=0,0727, G3=0,0147, G4=0,0307, G5=0,0253, G6=0,0960, G7=0,0173, G8=0,0333, G9=0,0480). A abrasão simulada aumentou a rugosidade superficial para todos os grupos, com exceção do Fortify (G2=0,0740, G7=0,0673) e Biscover (G7=0,0440), sendo os maiores valores apresentados pelo Lasting Touch (G4= 0,1253, G9=0,0980), seguido do Fill Glaze (G5=0,0933, G10= 0,0847). / This in vitro study evaluated the influence of the application of four surface sealers on the surface roughness of composite resins. Fifty specimens were divided into ten groups according to different patterns of composite resin and surface sealers, as follows: G1. Control with Concept resin; G2. Concept + Fortify; G3. Concept + Biscover; G4. Concept + Lasting Touch; G5. Concept + Fill Glaze; G6. Control with Esthet X; G7. Esthet X + Fortify; G8. Esthet X + Biscover; G9. Esthet X + Lasting Touch; G10. Esthet X + Fill Glaze. Specimens were made in four increments using a stainless steel matrix of 15x5x4mm and resin increments were polymerized with halogen lamp Curing Light 2500 (500mW/cm2) for 20 seconds each. After complete polymerization, specimens were stored in 100% humidity in distilled water at 37ºC for 24 hours. Following storage, specimens were polished using ascending grades (320, 600) of abrasive SiC paper under running water and the initial roughness was measured with a perfilometer Hommel Tester T100 basic (Hommelwerke GmbH ref. # 240851 - Schwenningem - Germany). Surface sealers were applied following the manufacturer\'s instructions and a new measurement of roughness was made. For the abrasive resistance test, specimens were submitted to 100.000 cycles of abrasive dentifrice brushing followed by surface roughness.. Qualitative analisys was made by using MEV. Results were submitted to Three-way ANOVA (p<0,05) and Tuckey\'s test to individual comparisons between different groups. Surface sealant application provided smoother surfaces for of composite resins tested (G2=0.0727, G3=0.0147, G4=0.0307, G5=0.0253, G6=0.0960, G7=0.0173, G8=0.0333, G9=0.0480). The abrasion test increased the surface roughness for all tested groups, except Fortify (G2=0,0740, G7=0,0673) and Biscover (G7=0,0440). Lasting Touch presented rougher surfaces (G4= 0,1253, G9=0,0980), followed by Fill Glaze (G5=0,0933, G10= 0,0847).

Introdução: Os benefícios do emprego do selante de fibrina no reforço de anastomoses pancreatico-jejunais, após ressecção duodenopancreática, visando a redução da incidência de fístula pancreática pós operatória (FPPO), ainda são questionáveis. Objetivo: Avaliar a influência do emprego do selante de fibrina na anastomose pancreatico-jejunal, após duodenopancreatectomia, na incidência de fístula, bem como suas consequências clínicas e os custos hospitalares. Metodologia: Estudo retrospectivo de 62 pacientes consecutivos submetidos a duodenopancreatectomia, divididos em dois grupos: 31 pacientes utilizando o selante de fibrina (GCS) e 31 pacientes sem o emprego de selante (GSS). As variáveis estudadas foram agrupadas em epidemiológicas, clínicas, laboratoriais, com destaque para a incidência de fístula pancreática, classificada segundo a definição do International Study Group on Pancreatic Fistula, suas complicações pós operatórias catalogadas segundo a classificação de Clavien e suas repercussões na assistência e nos seus custos avaliados pelo método de absorção com rateio simples de todas as despesas, exceto a despesa com medicamentos, tratada de forma separada. Resultados: Os grupos foram homogêneos para os parâmetros epidemiológicos, clínicos, e laboratoriais e não foram registradas diferenças significativas na comparação da evolução pós operatória e dos indicadores assistenciais hospitalares. Por outro lado, os custos hospitalares foram mais elevados no GCS, em relação ao GSS (p<0,0001). Conclusão: O emprego do selante de fibrina, no reforço da anastomose pancreatico-jejunal, em pacientes submetidos a duodenopancreatectomias, nas condições estudadas, não melhorou os resultados clínicos e assistenciais e ainda aumentou os custos hospitalares. / Introduction: The benefits of fibrin sealant employment in strengthening pancreatico-jejunal anastomosis after duodenopancreatic resection, reducing the incidence of pancreatic fistula postoperative (PFPO) are still questionable. Objective: To evaluate the influence of the use of fibrin sealant in pancreatico-jejunal anastomosis after pancreaticoduodenectomy in the incidence of fistula and its clinical consequences and hospital costs. Methodology: A retrospective study of 62 consecutive patients who underwent pancreaticoduodenectomy, divided into two groups: 31 patients using fibrin sealant (GCS) and 31 patients without the sealant employment (GSS). The variables were grouped into epidemiological, clinical, laboratory, especially the incidence of pancreatic fistula classified as defined by the International Study Group on Pancreatic Fistula, their postoperative complications cataloged according to Clavien rating and its repercussions on care and its costs assessed by the absorption method with simple apportionment of all expenses except the expenditure on medicines, treated separately. Results: The groups were homogeneous for clinical, epidemiological and laboratory parameters and no significant differences were recorded in the comparison given postoperative progress and hospital assistance indicators. Moreover, hospital costs were higher in GCS, with respect to GSS (p <0.0001). Conclusion: The use of fibrin sealant in pancreatojejunal anastomosis after pancreaticoduodenectomy, in the studied conditions, did not improve the results of care and also increased hospital costs

A estabilidade de cor é crucial para o sucesso de qualquer tipo de restauração estética, pois a alteração de cor das resinas é o maior motivo para as trocas das restaurações anteriores. O objetivo desse trabalho foi avaliar similaridade de cor, sua estabilidade e opacidade de três compósitos diretos (TPH - Dentsply; Charisma - Heraus Kulzer; Concept - Vigodent) protegidos com selantes de superfície (Fortify e Biscover - Bisco) e cianoacrilato (Super Bonder - Loctite Henkel). Para cada compósito foram obtidos 40 corpos-deprova que foram divididos em 4 grupos, segundo o tipo de proteção recebida:Grupo 1 - sem selantes (controle); Grupo 2 - cianoacrilato; Grupo 3 - selante Fortify e Grupo 4 - selante Biscover. Os corpos-de-prova tiveram sua cor e opacidade avaliadas (Espectrofotômetro PCB 6087 BYK GARDNER) sendo, em seguida, submetidos a envelhecimento artificial acelerado (EAA - Sistema C-UV, Comexim) por 384 horas. Após esse período, foram feitas as medidas finais de cor e opacidade. Foram realizadas análises em Microscopia Eletrônica de Varredura (MEV - Jeol JSM 7500 - SII, Sony, Tokyo, Japan) para verificação da modificação superficial dos corpos-de-prova, antes e após envelhecimento. Verificou-se que os compósitos não apresentaram os mesmos valores para as coordenadas L*, a* e b*, antes do EAA. Todos os compósitos, independentes da cobertura de superfície, apresentaram alteração de cor após o EAA considerada clinicamente inaceitável (&Delta;E>=3,3). A alteração na opacidade foi pequena para os grupos protegidos, sendo que os melhores resultados foram conseguidos com o selante Fortify. As superfícies analisadas por MEV protegidas com selantes de superfície apresentaram maior lisura superficial que quando protegidas com cianoacrilato, tanto antes quanto após EAA. Concluiu-se que matizes iguais de compósitos não apresentaram similaridade de cor entre as marcas comerciais avaliadas. Além disso, selantes de superfície comerciais não foram efetivos na manutenção da cor dos compósitos, entretanto auxiliam na manutenção da opacidade. / The color stability is crucial for the success of any type of aesthetic restoration because color alteration of composite resins is the main reason for the replacement of restorations in anterior teeth. The purpose of the study was to evaluate the color similarity, stability and opacity of three direct resin composites (TPH - Dentsply; Charisma - Heraus Kulzer; Concept - Vigodent) protected with surface sealant (Fortify and Biscover - Bisco) and cyanoacrylate (Super Bonder - Loctite Henkel). Forty specimens were done for each composite and divided into 4 groups (n=10) according to the surface protection: G1 - without sealant; G2 - cianoacrilate; G3 - Fortify and G4 - Biscover. The specimens had their color and opacity evaluated by reflection spectrophotometry (Spectrophotometer PCB 6087 BYK GARDNER) and were sequentially submitted to the accelerated artificial aging (AAA - C-UV System, Comexim) for 384 hours. After this period, final color and opacity measurements were made. Scanning Electron Microscopy (SEM - Jeol JSM 7500 - SII, Sony, Tokyo, Japan) were accomplished to verify the specimens\' alteration before and after the artificial aging. It were verified that composites did not present the same values for L*, a* and b* coordinates before AAA. All composites, regardless of the surface coat, presented color alteration after AAA considered clinically unacceptable (&Delta;E>3.3). The opacity alteration was small for the protected groups, and the best results were achieved with Fortify sealant. The surfaces analyzed by SEM protected with sealant displayed higher superficial smoothness than those protected with cyanocrylate before and after the AAA. It were concluded that composite resins of the same shade did not present color similarity among the testes products. Besides, surface sealants were not effective in maintaining composite color, but aid to maintain the opacity.

O objetivo deste estudo foi avaliar a resistência de união, ao ensaio de microtração, de selante (Clinpro, 3M) e sistemas adesivos (OptiBond FL, Kerr; OptiBond Solo, Kerr; OptiBond Solo Self-Etch Adhesive System (SE), Kerr) aplicados em superfícies oclusais de molares decíduos (n=32). Os produtos avaliados foram testados após serem aplicados de acordo com as recomendações dos fabricantes e após contaminação da superfície oclusal com saliva. Após armazenagem em água por 24h a 37ºC, cada dente foi secionado no plano mésio-distal e perpendicularmente à interface de união para obtenção de corpos-de-prova em forma de palito com seção transversal retangular e área aproximada de 0,6 mm 2 . Cada corpo-de-prova foi submetido ao teste de tração em máquina de ensaio universal a uma velocidade de 0,5 mm/min e os fragmentos armazenados para análise posterior do padrão de fratura em microscopia eletrônica de varredura. As fraturas foram classificadas em: adesiva mista, tipo 1 (fratura tanto de material restaurador, isto é associação de adesivo/resina composta, como do esmalte e o substrato predominante foi esmalte); adesiva mista, tipo 2 (fratura tanto de material restaurador como do esmalte e o substrato predominante foi o material restaurador); adesiva mista, tipo 3 (fratura tanto de material restaurador como do esmalte e houve distribuição homogênea de ambos); mista tipo 4 (fratura apenas de material restaurador, isto é, adesivo associado à resina composta) e; coesiva tipo 5 (fratura coesiva exclusivamente de um do substratos sendo esmalte ou resina composta). A análise estatística dos dados obtidos, relativos à resistência de união, usou como unidade experimental o dente. Os palitos perdidos em cada grupo foram incluídos no cálculo de resistência de cada dente. A contaminação salivar não influe nciou a perda de palitos. Não houve associação entre o padrão de fratura e os valores de resistência de união. As fraturas foram predominantemente mistas, não foi observada fratura coesiva exclusivamente de esmalte ou resina composta. Para os sistemas adesivos testados, nenhuma diferença significante foi observada entre os grupos com contaminação salivar ou não. OptiBond FL (34,5 ± 2,2 MPa) e Clinpro (45,1 ± 3,2 MPa) apresentaram valores de resistência de união similares e significativamente maiores do que o OptiBond Solo Plus (19,1 ± 2,3 MPa) e OptiBond Solo SE (9,8 ± 2,3 MPa) que foram equivalentes entre eles (p > 0,05). / The aim of this study was to evaluate the micro-tensile bond strength (mTBS) of a conventional sealant (Clinpro, 3M) and adhesive systems (OptiBond FL, Kerr; OptiBond Solo, Kerr; OptiBond Solo Self-Etch Adhesive System (SE), Kerr) on occlusal surface of primary molars (n=32). Sealant and adhesives were tested under manufacturers’ specifications and after contamination of the bonding site with saliva. After storage in distilled water at 37 º C for 24 h, the specimens were longitudinally sectioned perpendicular to the adhesive interface. Stick shape samples with cross-sectional areas of about 0.6 mm 2 were obtained and subjected to a tensile force in a universal testing machine at a crosshead speed of 0.5 mm/min. The bond failure modes were evaluated at scanning electron microscope and classified as following: mixed, type 1 (with cohesive failure of the neighboring substrates, wherein enamel was predominant); mixed, type 2 (with cohesive failure of the neighboring substrates, wherein adhesive/resin composite was predominant); mixed, type 3 (with cohesive failure of the neighboring substrates, wherein enamel and adhesive/resin composite was equally distributed); mixed, type 4 (with cohesive failure of the neighboring substrates, where there was only adhesive and resin composite, with none enamel fracture); cohesive, type 5 (failure exclusive within enamel or resin composite). The mean value of bond strength was calculated for each of the four teeth used per group, meaning that the experimental unit was the tooth. These were averaged to express the mean bond strength for every material at each group. The specimens lost due to pre-testing failure were included in the calculus of the mTBS of each tooth. Moisture did not influence sticks loss. There was not any association between failure mode and values of mTBS. The majority of fractures were mixed, none cohesive failure of enamel or composite resin was observed. For the tested adhesive systems no significant difference was observed between the groups under either saliva contamination or not. OptiBond FL (34.5 ± 2.2 MPa) and Clinpro (45.1 ± 3.2 MPa) showed similar values of mTBS and significantly higher than OptiBond Solo Plus (19.1 ± 2.3 MPa) and OptiBond Solo SE (9.8 ± 2.3 MPa) that were equivalent to each other (p>0.05).