Orientadores: Mario Fernando de Goes, Luis Roberto Marcondes Martins / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-03T15:59:52Z (GMT). No. of bitstreams: 1 Cordeiro_NaraPereirad'Abreu_D.pdf: 3561839 bytes, checksum: 125cbc91719d6a902ce59502debf7873 (MD5) Previous issue date: 2003 / Resumo: o objetivo deste estudo foi avaliar a resistência ao cisalhamento por extrusão (push out) entre a dentina intra-radicular e pinos de fibra de vidro nas regiões cervical, média e apical de raízes utilizando dois sistemas de cimentação adesiva. Foram selecionados vinte pré-molares inferiores unirradiculares recém extraídos por motivos ortodônticos, hígidos e livres de trincas. As coroas dos dentes foram removidas na altura da junção cemento esmalte. As polpas dentais foram removidas através de limas endodônticas e os condutos radiculares foram preparados com brocas de largo nO 5, com 8,Omm de penetração. As raízes foram divididas em dois grupos de 10: Grupo 1- pino fixados com o sistema adesivo autocondicionante ED Primer e cimento resinoso Panavia F; Grupo 2- pinos fixados com o sistema adesivo de frasco único Single Bond e cimento resinoso Rely X. Após a fixação dos pinos, as raízes foram mantidas em estufa a 37°C, por 24 h. A porção mais apical das raízes foi seccionada até a altura em que a raiz apresentasse 8,Omm de comprimento. Em seguida, as raízes foram seccionadas transversalmente e 3 discos de 2,7mm de altura foram obtidas e classificadas segundo a região cervical, média e apical do pino. O ensaio de resistência de união por extrusão foi realizado em máquina de ensaio universal Instron 4411 onde uma haste metálica com ponta ativa de 1,Omm de diâmetro produziu a carga para efetuar o deslocamento do pino do conduto radicular. Os valores médios de resistência de união por extrusão não apresentaram diferenças estatísticas significantes no terço cervical da raiz entre os dois materiais de fixação avaliados. Nas regiões média e apical do conduto, os valores de resistência de união apresentados pelo Sing/e Bond + Re/y X foram superiores e estatisticamente diferentes em relação aos valores apresentados pelo sistema ED Primer + Panavia F (p< 0,05). Para os dois materiais em estudo, não houve diferença estatística quando comparadas as regiões média e cervical do pino, porém apresentaram diferença estatística em relação à região apical (p< 0,05). Após o ensaio de cisalhamento por extrusão, os espécimes foram seccionados no sentido longitudinal para análise em microscopia eletrônica de varredura. A zona de interdifusão adesivo/dentina produzida pelo adesivo de frasco único Sing/e Bond apresentou-se mais espessa do que a zona de interdifusão apresentada pelo adesivo autocondicionante ED Primer. Houve áreas desmineralizadas com presença de túbulos dentinários abertos porém parcialmente preenchidos pela resina em ambos os grupos. Também foram observadas bolhas que variaram de tamanho e forma na camada de cimento junto à área da interface de união e mais constantes no terço apical das raízes. Palavras-chave: pino de fibra de vidro; cimento resinoso; sistema adesivo; resistência de união; "push out / Abstract: The purpose of this study was to evaluate the bond strength between fiber posts cemented in root dentin considering different depths of the roots (cervical, median and apical) and two luting materiais, through push out tests and to examine the integration among these components through scanning electron microscopy. Twenty sound bicuspids, tree trom cracks, extracted for orthodontic reasons, were selected. The crowns were removed at the cement enamel junction. The pulps were removed with endodontic reamers and the first 8,Omm of the canais were shaped with number 5 largo burs. The roots were divided into two groups of 10 each. The roots trom group 1 received fiber posts cemented with the self etching primer ED Primer and the composite resin Panavia F., while the roots of Group 2 received fiber posts cemented with the one bottle adhesive Single Bond and the composite resin Rely X. After the posts cementation, the roots were kept in humidity at 3-,0 C for 24 hours. The most apical part of the roots were sectioned until they were 8.0mm long. After that, the roots were sectioned transversally and three 2.7mm thick sections were obtained: cervical, median and apical. The push out test that evaluated bond strength between luting material and root dentin was carried out on an Instron (4411) testing machine. The specimens were positioned on a steel support platform with the post centered over a 2.0mm hole in the platform. A steel probe 1.0mm in diameter was centered over the post and used to apply force to the test specimens. Data from the push out test revealed no statistically significant differences at the cervical portion of the root between the two cementation systems tested. At the median and apical portion of the root, the bond strength values presented by the Sing/e Bond and Re/y X were superior and statistically different from those presented by ED Primer and Panavia F (P<O,05). After the push out test, the specimens were sectioned longitudinally for observation in scanning electron microscope. Afterwards, the specimens were gold sputtered to have their failure mode evaluated. The adhesive/dentin hybrid layer formed by the one bottle adhesive Sing/e Bond was thicker than the one formed by the self etching ED primer. There were zones of demineralization in the root dentin not filled with the adhesive for both groups. Many voids could be observed at the cernent layer close to the bonding area and they seemed to be more frequent at the apical portion of the roots / Doutorado / Dentística / Doutor em Clínica Odontológica

Magister Scientiae Dentium - MSc(Dent) / CAD/CAM crowns have become popular due to the many advantages associated with this technology. Optimal bonding adhesion is crucial for the durability of these indirect restorations and many factors influence this crucial step. Currently, there is no consensus or evidence-based guidelines on the best adhesion protocol for CAD/CAM crowns fabricated from hybrid materials. This study was aimed at investigating the influence of three types of resin cements on the shear bond strength of a hybrid CAD/CAM material in vitro.

Background . Little is known about the long-term clinical bonding effectiveness of the Fiber-reinforced composite (FRC) posts cemented with self-etch adhesive systems. Bond stability and longevity of the cemented post are adversely affected by physical and chemical factors over time, such as expansion and contraction stresses caused by thermal changes and occlusal load. This clinical condition can be simulated in vitro by thermocyclic loading; and bonding effectiveness can be evaluated by applying the micropush out test. Therefore, more in vitro studies are needed to evaluate the bond strength of the fiber posts cemented with different resin cement systems after simulating the artificial aging induced by thermocycling. The aim of this study was to compare the microtensile bond strength of two different resin cement systems (total etch, and self-etch resin cement system) used for cementation of fiber reinforced composite posts in three different aging periods using thermocycling. Methods . Following IRB approval, sixty freshly extracted bicuspid single rooted natural teeth were endodontically treated, and the post-spaces were prepared to receive a fiber-post cemented with either a total etch resin cement (Rely-X Ultimate) or with a self-etch resin cement (Rely-X Unicem). No thermocycling, 20,000 and 40,000 cycles was used to age the specimens. Teeth were randomly allocated into six different groups: G1 - Control: Rely-X Ultimate cement with no thermocycling. G2: Rely-X Ultimate cement with 20,000 thermocycling. G3: Rely-X Ultimate cement with 40,000 thermocycling. G4: Rely-X Unicem cement. G5: Rely-X Unicem cement. G6: Rely-X Unicem cement. Microtensile bond strength determined using a micropush out test on a universal testing machine (MTS). Additionally, the failure mode of each specimen was observed under a stereomicroscope (Olympus) at 40x magnification. Finally, one representative sample was randomly selected from each of the five failure modes for scanning electron microscope (SEM) examination of the surface morphology in order to obtain SEM images of the failure patterns at 29-70x magnifications. Statistical analysis: Nested general linear and generalized linear model was created to look for statistical significance. Level of significance was set at P < 0.05. Results . No significant differences were found on the bond strength between the two types of resin cement systems (total etch and self-etch). Regarding the thermocycling effect, the bond strengths of the group of 40,000 cycles was significantly lower than the 20,000 cycle group. In addition, the bond strengths of the specimens collected from the coronal third of the root were significantly lower than the specimens from the apical third. A Fisher's Exact test was applied to evaluate the failure mode differences, and showed statistically significant differences between the groups. Conclusions . The bond strength to the root canal dentin did not vary with the type of resin cement systems (total-etch vs self-etch). The microtensile bond strength values of FRC posts were significantly affected by increasing the thermocycling, and were significantly different among the different longitudinal levels of the root canal.

Objectives: To evaluate and compare the color of porcelain veneers with try-in paste in relation to porcelain veneers with permanent cement. Also, to evaluate and compare combinations of three different shades and thicknesses of porcelain veneers and three cement shades before and after final cementation. Additionally, to evaluate and compare the color of porcelain veneers with cured permanent cement before and after aging. Background: Porcelain veneers and ceramic restorations have become one of the most popular approaches in the anterior area due to their natural appearance and esthetics. However, more conservative approaches have led to thinner restorations with increased translucency. A potential drawback to these restorations is that any color change in the luting cement can become clinically visible, and possibly affect esthetic appearance. Methods: One hundred and eight specimens were cut from feldspathic porcelain blocs (Vitablocs Mark II for CEREC). Three different Vita 3D- Master 1M1, 2M2, and 3M1 shades were assessed. All specimens were 12 x 14 mm, with three different thicknesses of 0.3, 0.5, and 1.0 mm. Light-cured resin cement (Variolink Veneer, Ivoclar Vivadent) with three different shades was used. The specimen color alone, with the try-in paste, and with pre-cured and post-cured resin cement was measured using a spectrophotometer (Color Eye 7000A), which measures CIE-L*a*b* values. Specimens were subjected to 30,000 cycles of accelerated aging (Themo-cycling, Sarbi Dental Enterprises Inc.). Color measurement for all specimens was performed again and ∆E values between groups been calculated. Statistical analysis was performed using one-way and three-way ANOVA, with level of significant set at α=0.05, to assess differences between groups. This was followed by post hoc Tukey's tests. Results: Statistical analysis showed a significant difference between try-in paste and corresponding cured resin cement. Pre-cured and post-cured resin cement values showed a significant difference between cement shades. Moreover, statistically significant differences were found between post-cured cement and after 30,000 cycles of thermo-cycling. Conclusions: The final color of porcelain veneers was highly affected by the different shades of resin cement and by the thicknesses of the porcelain veneer. The use of higher ceramic thickness decreased the ∆E values when compared to thinner veneers. Also, color stability of ceramic veneer restorations luted with resin cement, was significantly influenced by the aging.

Indiana University-Purdue University Indianapolis (IUPUI) / Background and Rationale: As compared with glass-based ceramics, zirconia has gained considerable popularity in restorative dentistry due to its superior mechanical properties. Clinically, however, zirconia ceramics pose a significant challenge regarding the achievement of a reliable and durable bond to resin-based cements. Thus far, it has been established that zirconia bond to resin-based cements can be enhanced after different surface conditioning methods, such as airborne particle abrasion with aluminum oxide particles. Meanwhile, another major issue pertaining to bonding of ceramic restorations is related to its potential contamination before cementation. Briefly, after sandblasting and clinical try-in procedures, zirconia can be contaminated with saliva and/or blood. As with many metals, zirconium shows a strong affinity towards the phosphate group found in saliva and other fluids, which reacts with the zirconia surface and makes bonding very difficult. Recently, a new cleaning agent called Ivoclean® (Ivoclar-Vivadent), which is an alkaline suspension of zirconium oxide particles, has been introduced in the market to remove contamination from zirconia in an effort to improve bonding to resin cements. Objective: The purpose of this study was to evaluate the influence of saliva contamination and the effect of several cleaning methods, including Ivoclean on resin bond strength to zirconia. Materials and Methods: Eighty square-shaped specimens (ϕ = 12 mm x 12 mm x 3 mm) of yttria-stabilized full-contour zirconia (Diazir®, Ivoclar-Vivadent, Amherst, NY) were sectioned from zirconia blocks using a water-cooled diamond blade. Then, these specimens were embedded in acrylic resin, and their surfaces gradually finished with silicon carbide papers (600 grit to 1200 grit). The prepared zirconia surfaces were sandblasted with 50-μm aluminum oxide particles for 15 s, under 2.5 bars and from distance of 10 mm. After sandblasting the specimens were cleaned in an ultrasonic bath containing distilled water for 5 min and air-dried for 10s. All samples were equally divided into 4 groups (n = 20) according to the cleaning method. Airborne particle abraded specimens without contamination was served as the control group. Remaining groups were contaminated with saliva, and subjected to different cleaning protocols, namely: Ivoclean®, 70% isopropanol, and no treatment. Two resin cement buttons (Multilink – Ivoclar-Vivadent, Amherst, NY) were built over each zirconia surface and light-cured following the manufacturer recommendations. The influence of contamination and surface cleaning methods on ceramic bond durability were examined after 24 h on half of the samples in each group (n = 10, n = 20), and the other half (n = 10, n = 20) specimens will undergo 6000 thermocycles (TC) before shear bond testing in the universal testing machine. Conclusion of Expected Outcomes: The shear bond strength of resin cement to zirconia led to a significant improvement after cleaning with Ivoclean both immediately and after thermal aging.

O objetivo deste estudo foi avaliar a estabilidade de cor de cimentos resinosos para fixação de restaurações cerâmicas em diferentes espessuras submetidas ao envelhecimento artificial acelerado (EAA). Foram utilizados 60 molares humanos hígidos, cujas porções radiculares foram incluídas em matriz de PVC (15 mm de diâmetro) com resina acrílica e as faces oclusais foram planificadas, 30 em esmalte e 30 até dentina, sendo que 10 dentes de cada substrato foram considerados gruposcontrole para os dentes restaurados. Foram obtidos 40 corpos de prova em cerâmica (IPS e-max Ceram, Ivoclar Vivadent), com 0,5 mm e 1,0 mm, que foram separados aleatoriamente em dois grupos (n=10) segundo o tipo de cimento resinoso dual utilizado para fixação: convencional (Variolink II, Ivoclar/Vivadent) ou auto-adesivo (Rely-X Unicem, 3M ESPE). Além desses, foram obtidos 10 corpos de prova de cada cimento resinoso (0,5mm), considerado grupo-controle para os materiais. Todas as amostras foram mantidas em estufa a 37ºC por 24h, após o qual foram realizadas as leituras de cor iniciais (Vita EasyShade, VITA). Em seguida, foram submetidas ao EAA por 580 horas, após o qual novas leituras de cor foram realizadas. Foi avaliada estabilidade de cor e a luminosidade. Os dados de estabilidade de cor (&Delta;E) e luminosidade (&Delta;L) obtidos foram submetidos a análise estatística (2-way ANOVA, Bonferroni, p<0,05) e a comparação dos materiais com os grupos controles foi realizada utilizando 1-way ANOVA e teste de Tukey (p<0,05). O cimento dual convencional apresentou maior alteração de cor e luminosidade quando sob a restauração de 0,5mm, diferente estatisticamente (p<0,05) de restaurações de 1,0mm. Não houve diferença estatisticamente significante (p>0,05) quando comparados os materiais. Quando analisadas a estabilidade de cor e luminosidade dos grupos com restaurações em relação aos grupos-controle, verificou-se que ambos os cimentos apresentaram maiores alterações, diferente estatisticamente (p<0,05) dos demais grupos, com exceção ao grupo de 0,5mm em relação ao Grupo esmalte quando analisado o cimento dual convencional (p>0,05). Concluiu-se que quanto menor a espessura da restauração, maior a alteração de cor e de luminosidade do cimento dual convencional. As alterações do cimento autoadesivo não dependem da espessura da restauração. / The aim of this study was to evaluate the color stability of resin cements for luting ceramic restorations with different thicknesses submitted to accelerated artificial aging (AAA). Sixty sound human molars had their root portions embedded in PVC rings (15-mm diameter) with acrylic resin. Their occlusal surfaces were flattened according two substrates: 30 surfaces until enamel and 30 until dentin. Then, 10 teeth of each substrate were considered as control groups for restored teeth. Forty specimens of ceramic (IPS e-max Ceram, Ivoclar Vivadent) were obtained with two different thicknesses (0.5 mm and 1.0 mm) and were randomly separated into two groups (n = 10) according to the type of the Dual resin cement used for luting: conventional (Variolink II, Ivoclar / Vivadent) or self-adhesive (Rely-X Unicem, 3M ESPE). Also, 10 specimens (0.5 mm) of each cement were obtained to be considered as control groups for materials. All specimens were stored at 37º C for 24 hours, and initial color readings (Vita Easyshade, VITA) were performed. Then, they were submitted to AAA for 580 hours, and final color readings were taken. Color stability and brightness were evaluated. Data of color stability (&Delta;E) and brightness (&Delta;L) were statistically analyzed (2- way ANOVA, Bonferroni, p<0.05) and the comparison of materials with control groups was performed using one-way ANOVA and Tukeys test (p<0.05). The conventional dual cement showed the greatest change in color and brightness when under restorations of 0.5 mm, statistically different (p<0.05) to restorations of 1.0 mm. There was no statistically significant difference (p>0.05) when comparing materials. When analyzing the color stability and brightness of restorations groups compared to control groups, both cements showed greater changes, statistically different (p<0.05), than other groups, except for the group of 0.5 mm in relation to enamel group when the dual conventional cement was analyzed (p>0.05). It was concluded that the smaller the thickness of the restoration, the greater the color and brightness changes of the dual conventional cement. Changes of the self-adhesive cement do not depend on the thickness of the restoration.

Este estudo teve como objetivo avaliar, através de testes de tração, a resistência de união de pinos pré-fabricados, com diferentes graus de translucidez, à dentina bovina, utilizando três tipos de cimentos resinosos. Noventa incisivos bovinos tiveram suas coroas anatômicas separadas das raízes através de uma secção perpendicular ao longo eixo dos dentes na junção amelocementária, de modo que as raízes apresentassem 14 mm de comprimento. Os condutos radiculares foram tratados endodonticamente e os espécimes, mantidos em água destilada a 37°C por 7 dias. Após esse período, foi realizada a desobturação de 7 mm de profundidade de cada conduto para a cimentação dos três tipos de pino: Exacto (Angelus), translúcido; Reforpost fibra de vidro (Angelus), branco; e Reforpost fibra de carbono (Angelus), negro e opaco. Três tipos de cimentos resinosos foram utilizados de acordo com as recomendações dos fabricantes: o cimento dual auto-adesivo Rely X U100 (3M ESPE); o cimento dual Rely X ARC (3M ESPE), associado ao sistema adesivo autopolimerizável Scotchbond Multi-Uso Plus (3M ESPE); e o cimento de ação exclusivamente química Cement Post (Angelus), associado ao sistema adesivo Fusion Duralink (Angelus), constituindo 9 grupos experimentais (n=10). Após a armazenagem dos corpos de prova em água destilada a 37º C por 7 dias, foi realizado o teste de tração no aparelho de ensaio mecânico da marca Kratos Equipamentos, a uma velocidade de 0,5mm/min até a ruptura dos mesmos. Para determinar a tensão de tração, foi calculada a área de adesão de cada espécime. Os dados foram analisados estatisticamente através da Análise de Variância e do teste de Kruskal-Wallis, com grau de significância de 5%. Os espécimes foram examinados através de um microscópio óptico Olympus (Tokyo, Japão), com 20x de aumento, para avaliação do modo de fratura. Em relação às variáveis estudadas, verificou-se que: o pino Exacto, com maior translucidez e maior conicidade, apresentou valores de resistência à tração significativamente inferiores do que os pinos Reforpost Fibra de Vidro e Reforpost Fibra de Carbono, quando utilizado o cimento Rely X ARC; o cimento dual auto-adesivo Rely X U100 apresentou menores valores de resistência à tração do que cimento dual Rely X ARC quando utilizados os pinos Reforpost Fibra de Vidro e Reforpost Fibra de Carbono; e o cimento de polimerização química Cement Post apresentou menores valores de resistência à tração em relação aos cimentos duais, independente do tipo de pino testado. Quanto à análise microscópica, observou-se que os cimentos resinosos aderiram mais aos pinos do que à dentina radicular. Portanto, a translucidez dos pinos não contribuiu para aumentar a resistência à tração dos cimentos resinosos duais em nenhum dos grupos testados. / This study aimed to evaluate, through tensile test, the bond strength of prefabricated posts with different degrees of translucency, using three types of resin cements. Ninety bovine incisors were selected and sectioned at the cemento-enamel junction. The root canals were endodontically treated and the specimens were stored in distilled water at 37°C for 7 days. After this period, a 7-mm-deep post space was prepared for the cementation of three types of posts: Exacto (Angelus), translucent; Fiberglass Reforpost (Angelus), white; and Carbon Fiber Reforpost (Angelus), black and opaque. Three types of resin cements were used according to manufacturers\' instructions: the self-adhesive dual cement Rely X U100 (3M ESPE); the dual cement Rely X ARC (3M ESPE), associated with autopolymerized adhesive system Scotchbond Multi-Uso Plus (3M ESPE), and the self-cured cement Cement Post (Angelus), associated with the autopolymerized adhesive system Fusion Duralink (Angelus), constituting nine experimental groups (n = 10). After the storage of the specimens in distilled water at 37°C for 7 days, the tensile test was performed with a universal test machine at a crosshead speed of 0.5 mm/min. To determine the bond strength, the bonding area of each specimen was calculated. The data were statistically analyzed by ANOVA followed by Kruskal-Wallis test, with a significance level of 5%. The dislodged posts were examined microscopically (Olympus; Tokyo, Japan) at x20 magnification to determine the type of failure. Regarding the variables studied, it was found that: the Exacto post, more translucent and tapered, had significantly lower tensile bond strength than Fiberglass Reforpost and Carbon Fiber Reforpost when used the dual cement Rely X ARC; the dual self-adhesive cement Rely X U100 showed lower tensile bond strength than the dual cement Rely X ARC, when used Fiberglass Reforpost and Carbon Fiber Reforpost; regardless of the type of post tested, the self-cured cement Cement Post had lower tensile strength compared to dual cements. It was observed microscopically that resin cements adhered more to the posts than to the root dentin. Therefore, the translucency of the posts had not contributed to increase the tensile strength of dual-curing resin cements in all groups tested.

Avaliou-se a resistência de união do pino de fibra de vidro à dentina cimentado com quatro agentes cimentantes, por meio do teste push-out realizado após 24 horas e seis meses de armazenagem. Foram selecionados 80 dentes humanos uniradiculares, tratados endodonticamente e divididos aleatoriamente em quatro grupos (n=20), variando-se o tipo de cimento utilizado: grupo I: cimento de ionômero de vidro reforçado com resina (Fuji PlusTM, GC Corp., Tokyo, Japan); grupo II: cimento resinoso usando sistema adesivo convencional de 3 passos de aplicação (RelyX ARC + Scotchbond Multi-purpose, 3M ESPE, St Paul, MN, USA); grupo III: cimento resinoso usando sistema adesivo autocondicionante de 1 passo de aplicação (PanaviaTM F, Kuraray, Osaka, Japan); e grupo IV: cimento resinoso auto-adesivo (BisCemTM, Bisco Inc., Schaumburg, IL). Cada grupo foi subdividido em dois subgrupos (N=10) variando-se o tempo de armazenagem (24 horas e seis meses). O teste de push-out foi realizado com uma velocidade de 1,0 mm/min, e os resultados expressos em Mega Pascal (MPa). Após o teste de push-out, todos os espécimes foram observados em microscópio óptico de fluorescência (40x) e analisado o tipo de falha apresentado entre o complexo pino/cimento/dentina radicular. Os valores médios de resistência (MPa) foram submetidos ao teste ANOVA a dois critérios e de Tukey (p<0,005). A análise estatística mostrou: 1) Diferenças significativas na resistência de união entre os cimentos utilizados, sendo que a média total do cimento resinoso RelyXTM ARC + ScotchbondTM MultipurposeTM foi superior aos dos outros cimentos após 24 horas; 2) A resistência de união dos cimentos resinosos RelyXTM ARC + ScotchbondTM MultipurposeTM e PanaviaTM F foram superiores aos outros cimentos quando testados após seis meses de armazenagem e não houve diferença significativa entre eles; 3) Após seis meses de armazenagem, observou-se um aumento na resistência de união de todos os cimentos; 4) Na análise por terços, foi observado que tanto após 24 horas quanto após seis meses, o terço cervical teve uma maior resistência de união do que o terço médio e apical; 5) Foram observadas predominantemente falhas mistas, apresentado-se na maioria dos casos a combinação de falha adesiva na interface pino/cimento e na interface cimento/dentina para todos os grupos. Concluiu-se que a resistência de união aumentou após seis meses de armazenagem graças possivelmente à expansão higroscópica e aumento da retenção friccional. / The bond strength of a glass fiber post luted to dentin with four luting agents was evaluated using the push-out test, after 24-hours and six months of storage. Eighty human single-routed teeth was selected, endodontically treated and randomly divided into four groups (n=20), modifying the luting agent used: group I: resin modified glass-ionomer (Fuji PlusTM, GC Corp., Tokyo, Japan); group II: resin cement using total-etch, three step adhesive system (RelyX ARC + Scotchbond Multi-purpose, 3M ESPE, St Paul, MN, USA); group III: resin cement using self-etch one step adhesive system (PanaviaTM F, Kuraray, Osaka, Japan); and group IV: self-adhesive resin cement (BisCemTM, Bisco Inc., Schaumburg, IL). Each group was, then, subdivided into two subgroups (n=10) modifying the storage period (24-hours and six months). The push-out test was performed with a cross-speed of 1,0 mm/min, and the results expressed in Mega Pascal (MPa). After the test, all specimen interfaces were examined with the aid of a fluorescence optic microscope (40x) to dertemine the type of failure at the complex post/cement/dentin. The mean values of the bond strength (MPa) were analyzed with the two-way ANOVA and Tukey test (p<0,005). The statistical analysis showed: 1) Significant difference in the bond strength between the luting agents, in wich the mean total value of the resin cement RelyXTM ARC + ScotchbondTM MultipurposeTM was the highest after 24 hours; 2) The bond strength of the resin cement RelyXTM ARC + ScotchbondTM MultipurposeTM and PanaviaTM F were higher than the others luting agents when evaluated after six months, and there was no significant difference among both of them; 3) An increase in the bond strength of all luting agents after six months of storage in distilled water; 4) That the cervical third had a higher bond strength compared to the middle and apical thirds for all materials, during third analysis after 24-hours and six months of storage; 5) Predominantly, it was observed mixed failures, in the majority of the cases, with a combination of adhesive failure in the post/luting agent interface and in the luting agent/radicular dentin interface. Therefore, can be concluded that the bond strength of a glass fiber post luted to dentin with different luting agents can increase after six months of storage, possibly contributed by hygroscopic expansion and the increase of the frictional retention.

O objetivo deste estudo foi avaliar a estabilidade de cor de cimentos resinosos para fixação de restaurações cerâmicas em diferentes espessuras submetidas ao envelhecimento artificial acelerado (EAA). Foram utilizados 60 molares humanos hígidos, cujas porções radiculares foram incluídas em matriz de PVC (15 mm de diâmetro) com resina acrílica e as faces oclusais foram planificadas, 30 em esmalte e 30 até dentina, sendo que 10 dentes de cada substrato foram considerados gruposcontrole para os dentes restaurados. Foram obtidos 40 corpos de prova em cerâmica (IPS e-max Ceram, Ivoclar Vivadent), com 0,5 mm e 1,0 mm, que foram separados aleatoriamente em dois grupos (n=10) segundo o tipo de cimento resinoso dual utilizado para fixação: convencional (Variolink II, Ivoclar/Vivadent) ou auto-adesivo (Rely-X Unicem, 3M ESPE). Além desses, foram obtidos 10 corpos de prova de cada cimento resinoso (0,5mm), considerado grupo-controle para os materiais. Todas as amostras foram mantidas em estufa a 37ºC por 24h, após o qual foram realizadas as leituras de cor iniciais (Vita EasyShade, VITA). Em seguida, foram submetidas ao EAA por 580 horas, após o qual novas leituras de cor foram realizadas. Foi avaliada estabilidade de cor e a luminosidade. Os dados de estabilidade de cor (&Delta;E) e luminosidade (&Delta;L) obtidos foram submetidos a análise estatística (2-way ANOVA, Bonferroni, p<0,05) e a comparação dos materiais com os grupos controles foi realizada utilizando 1-way ANOVA e teste de Tukey (p<0,05). O cimento dual convencional apresentou maior alteração de cor e luminosidade quando sob a restauração de 0,5mm, diferente estatisticamente (p<0,05) de restaurações de 1,0mm. Não houve diferença estatisticamente significante (p>0,05) quando comparados os materiais. Quando analisadas a estabilidade de cor e luminosidade dos grupos com restaurações em relação aos grupos-controle, verificou-se que ambos os cimentos apresentaram maiores alterações, diferente estatisticamente (p<0,05) dos demais grupos, com exceção ao grupo de 0,5mm em relação ao Grupo esmalte quando analisado o cimento dual convencional (p>0,05). Concluiu-se que quanto menor a espessura da restauração, maior a alteração de cor e de luminosidade do cimento dual convencional. As alterações do cimento autoadesivo não dependem da espessura da restauração. / The aim of this study was to evaluate the color stability of resin cements for luting ceramic restorations with different thicknesses submitted to accelerated artificial aging (AAA). Sixty sound human molars had their root portions embedded in PVC rings (15-mm diameter) with acrylic resin. Their occlusal surfaces were flattened according two substrates: 30 surfaces until enamel and 30 until dentin. Then, 10 teeth of each substrate were considered as control groups for restored teeth. Forty specimens of ceramic (IPS e-max Ceram, Ivoclar Vivadent) were obtained with two different thicknesses (0.5 mm and 1.0 mm) and were randomly separated into two groups (n = 10) according to the type of the Dual resin cement used for luting: conventional (Variolink II, Ivoclar / Vivadent) or self-adhesive (Rely-X Unicem, 3M ESPE). Also, 10 specimens (0.5 mm) of each cement were obtained to be considered as control groups for materials. All specimens were stored at 37º C for 24 hours, and initial color readings (Vita Easyshade, VITA) were performed. Then, they were submitted to AAA for 580 hours, and final color readings were taken. Color stability and brightness were evaluated. Data of color stability (&Delta;E) and brightness (&Delta;L) were statistically analyzed (2- way ANOVA, Bonferroni, p<0.05) and the comparison of materials with control groups was performed using one-way ANOVA and Tukeys test (p<0.05). The conventional dual cement showed the greatest change in color and brightness when under restorations of 0.5 mm, statistically different (p<0.05) to restorations of 1.0 mm. There was no statistically significant difference (p>0.05) when comparing materials. When analyzing the color stability and brightness of restorations groups compared to control groups, both cements showed greater changes, statistically different (p<0.05), than other groups, except for the group of 0.5 mm in relation to enamel group when the dual conventional cement was analyzed (p>0.05). It was concluded that the smaller the thickness of the restoration, the greater the color and brightness changes of the dual conventional cement. Changes of the self-adhesive cement do not depend on the thickness of the restoration.

Made available in DSpace on 2017-07-24T19:21:56Z (GMT). No. of bitstreams: 1 Thaynara Faelly Boing.pdf: 1819408 bytes, checksum: 786153168eac139f5217b66b5e8291d4 (MD5) Previous issue date: 2015-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The purpose of this study was to evaluate the influence of two polymerization techniques on conversion degree (DC) of the resin cements and on retention of glass fiber posts in the different thirds of root dentine. For this purpose, it was selected twenty extracted mandibular premolars, which were sectioned after the cementumenamel junction, and the roots were treated endodontically. After a week, the posts spaces were prepared and the roots were randomly divided into two groups (n=10),according to the mode of polymerization of the dual resin cement (RelyX™ U200 – 3M ESPE): GFC - activation mode Continuous and GFS - activation mode Soft start (Ramp). The intraradicular posts (White Post DC - FGM) were cemented according to the manufacturer's recommendations. After storage in distilled water at 37 ° C for one week, the roots were cross-sectioned in six discs of 1 mm thickness each, and the thirds coronary (TC), medium (TM) and apical (TA) of the root canal were identified.To assess the degree DC the specimens were submitted to Micro-Raman spectroscopy, and the bond strength by the push-out test at a cross-head speed of 0.5 mm/min. The data were be statistically analyzed by two-way ANOVA and Tukey’s test for contrast of means (α = 0.05). The average values of degree of conversion and standard deviation (SD ) for each group were: GFC : 75.66 ± 5.51 , GFS : 77.38 ± 5.66, compared to thirds GFC : TC : 73.87 ± 5.50, TM : 74.59 ± 4.86 and TA : 78.50 ± 5.57 , GFS : TC : 77.79 ± 6.16 , TM : 77.14 ± 5.77 and TA : 77.21 ± 5.79 . There was no significant difference between the techniques of photoactivation or between root thirds. For bond strength ( MPa ) mean (SD) values and standard deviation were : GFC : 18.46 ± 6.23 , GFS : 22.88 ± 5.76 , compared to thirds , GFC : TC : 14.32 ± 3.40 , TM : 15.75 ± 3.20 , TA : 25.30 ± 4.89 , GFS : TC : 19.83 ± 3.97 , TM : 22.21 ±5.59 , MT : 26 , 59 ± 5.79 . The activation mode GFS was statistically higher than the 11 GFC (p = 0.036). And the apical obtained resistance values statistically superior compared to other union -thirds (p < 0.001). It can be concluded that the bond strength was significantly affected by the technique of photoactivation and the root region, and that the degree of conversion was not affected either by photoactivation technique nor the root region. / O propósito deste estudo foi avaliar a influência de duas técnicas de fotopolimerização no grau de conversão (GC) de cimentos resinosos, bem como na retenção de pinos de fibra de vidro à dentina nos diferentes terços radiculares. Foram utilizados vinte pré-molares inferiores humanos extraídos seccionados transversalmente abaixo da a junção cemento-esmalte, cujas raízes foram tratadas endodonticamente. Após uma semana foi realizado o preparo padronizado dos condutos, e as raízes foram divididas aleatoriamente em dois grupos (n=10), de acordo com o modo de fotopolimerização do cimento resinoso dual (RelyX U200 – 3M ESPE): GFC - modo de ativação Contínuo e GFS - modo de ativação início Suave (Ramp). Os pinos intrarradiculares (White Post DC - FGM) foram cimentados de acordo com as recomendações do fabricante. Após o armazenamento em água destilada a 37°C por uma semana, as raízes foram seccionadas transversalmente em seis discos com 1 mm de espessura cada, e os terços coronário (TC), médio (TM) e apical (TA) do canal radicular foram identificados. Para avaliação do GC os espécimes foram submetidos à Espectroscopia Micro-Raman e para verificação da resistência de união (RU) ao teste de push out, realizado a uma velocidade de 0,5 mm/min. Os dados obtidos de GC e RU foram submetidos ao teste de análise de variância (ANOVA) 2 fatores, e ao pós teste de Tukey para comparação das médias (α = 0,05). Os valores médios de grau de conversão (%) e desvio padrão (DP) para cada grupo foram: GFC: 75,66±5,51, GFS: 77,38±5,66, em relação aos terços, GFC:TC: 73,87±5,50, TM: 74,59±4,86 e TA: 78,50±5,57, GFS: TC: 77,79±6,16, TM: 77,14±5,77 e TA: 77,21±5,79. Não houve diferença significativa entre as técnicas de fotoativação e nem entre os terços radiculares. Para resistência de união (MPa) os valores médios e desvio padrão (DP) foram: GFC: 18,46±6,23, GFS: 22,88±5,76, em relação aos terços, GFC: TC: 14,32±3,40, TM: 15,75±3,20, TA: 25,30±4,89, GFS:TC: 19,83±3,97, TM: 22,21±5,59, TA: 26,59±5,79. O modo de ativação GFS foi 9 estatisticamente superior em relação ao GFC (p=0,036). E o terço apical obteve valores de resistência de união estatisticamente superiores em relação ao outros terços (p<0,001). Pode-se concluir que a resistência de união foi afetada significativamente pela técnica de fotoativação e pela região radicular, e que o grau de conversão não foi afetado nem pela técnica de fotoativação e nem pela região radicular.