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Effect of curing protocol on the polymerization of dual-cured resin cements

PEREIRA, Sonia G.; FULGENCIO, Rogerio; NUNES, Teresa G.; TOLEDANO, Manuel; OSORIO, Raquel; CARVALHO, Ricardo Marins
Fonte: ELSEVIER SCI LTD Publicador: ELSEVIER SCI LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
86.51%
Objectives. The purpose of this study was to evaluate how curing protocol affects the extent of polymerization of dual-cured resin cements. Methods. Four commercial resin cements were used (DuoLink, Panavia F 2.0, Variolink II and Enforce). The extent of polymerization of the resin cements cured under different conditions was measured using a (1)H Stray-Field MRI method, which also enabled to probe molecular mobility in the kHz frequency range. Results. Resin cements show well distinct behaviours concerning chemical cure. Immediate photo-activation appears to be the best choice for higher filler loaded resin cements (Panavia F 2.0 and Variolink). A photo-activation delay (5 min) did not induce any significant difference in the extent of polymerization of all cements. Significance. The extent of polymerization of dual-cured resin cements considerably changed among products under various curing protocols. Clinicians should optimize the materials choice taking into account the curing characteristics of the cements. (C) 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.; CAPES (Brazil)[O565-07-5]; Portuguese Foundation for Science and Technology[PDCT/SAU-BMA/55395/2004]; [MAT2008-02347/MAT]; [JA P07-CTS-2568]; [P08-CTS-3944]

Efeito da solução de clorexidina a 2% a um cimento ionomérico e um resinoso na adesão de pinos de fibra de vidro em raízes bovinas após 7 dias e 6 meses de armazenamento; Effect of 2% chlorhexidine solution on bonding of a glass ionomer cement and a resin cement to bovine root dentin after 7-day and 6-month storage

Araújo, Diana Ferreira Gadêlha de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 08/03/2013 PT
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76.59%
Este trabalho avaliou a influência do uso de solução de clorexidina a 2% (CHX) na resistência de união de pino de fibra de vidro à dentina radicular, utilizando um agente cimentante ionomérico modificado por resina e um cimento resinoso dual com sistema adesivo convencional, nos terços cervical, médio e apical. Oitenta raízes bovinas foram selecionadas, cortadas em 17mm e tratadas endodonticamente para em seguida serem divididas em 8 grupos: ARC (RelyX ARC/ScothBond MultiPurpose- cimento resinoso); ARC+CHX (ARC associado a CHX); RL (RelyX Luting 2- ionômero de vidro); RL+CHX (RL associado a CHX). Os espécimes de cada protocolo foram divididos em grupos de 7 dias ou 6 meses de armazenamento, depois de serem restaurados com pino de fibra de vidro cônico Exacto. Após 24 horas da cimentação, as raízes foram seccionadas perpendicularmente ao longo eixo e identificadas quanto à região, obtendo-se fatias (1mm de espessura). Após o tempo de armazenamento proposto, todas as fatias foram submetidas ao teste de extrusão (push-out) com célula de carga a 0,5mm/min. Os dados foram tabelados considerando as variáveis dos diferentes agentes cimentantes, uso ou não de solução de clorexidina, terços radiculares e tempo de armazenamento. Depois de testados...

Influência da opacidade da infraestrutura do dissilicato de lítio na polimerização do cimento resinoso dual, por teste de microdureza Knoop; Influence of opacity the lithium disilicate infrastructure in dual-cured resin cement by Microhardness knoop

Costa Neto, Dylton Augusto Rodrigues da
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 25/06/2013 PT
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76.48%
As restaurações indiretas em sistemas totalmente cerâmicos desenvolveram-se visando à obtenção de próteses com melhor capacidade de mimetismo do dente natural. Além das propriedades óticas, essas restaurações devem ter adesão ao substrato de suporte, de modo a promover a união entre a cerâmica, o esmalte e a dentina, formando um corpo único, permitindo a transferência de tensões da restauração para a estrutura dental. Alguns fatores como: composição, espessura, opacidade e a cor do material cerâmico podem interferir na passagem de luz e, consequentemente, diminuir o grau de conversão do cimento, limitando o alcance de suas propriedades mecânicas e prejudicando o desempenho clínico. Dessa forma, este trabalho teve por objetivo avaliar a influência de diferentes níveis de opacidade da infraestrutura do dissilicato de lítio na polimerização de um cimento resinoso dual. Foram utilizados quatro discos de cerâmica (IPS e.max Press, IvoclarVivadent, Schaan, Liechtenstein), um para cada opacidade da infraestrutura (HT, LT, MO e HO) recobertas por sua respectiva cerâmica de cobertura (IPS e.max ceram na cor A3), e um grupo de cimento sem a cerâmica interposta (grupo-controle). Para cada grupo foram polimerizados 15 corpos de prova de cimento resinoso (Variolink II...

Influence of activation modes on diametral tensile strength of dual-curing resin cements.

Fonseca, Renata Garcia; Santos, Juliana Gomes dos; Adabo, Gelson Luis
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 267-271
ENG
Relevância na Pesquisa
76.84%
In metallic restorations, the polymerization of dual-curing resin cements depends exclusively on chemical activation. The effect of the lack of photoactivation on the strength of these cements has been rarely studied. This study evaluated the influence of activation modes on the diametral tensile strength (DTS) of dual-curing resin cements. Base and catalyst pastes of Panavia F, Variolink II, Scotchbond Resin Cement, Rely X and Enforce were mixed and inserted into cylindrical metal moulds (4 x 2 mm). Cements were either: 1) not exposed to light (chemical activation = self-cured groups) or 2) photoactivated through mylar strips (chemical and photo-activation = dual-cured groups) (n = 10). After a 24 h storage in 37 masculineC distilled water, specimens were subjected to compressive load in a testing machine. A self-curing resin cement (Cement-It) and a zinc phosphate cement served as controls. Comparative analyses were performed: 1) between the activation modes for each dual-curing resin cement, using Students t test; 2) among the self-cured groups of the dual-curing resin cements and the control groups, using one-way ANOVA and Tukeys test (alpha = 0.05). The dual-cured groups of Scotchbond Resin Cement (53.3 MPa), Variolink II (48.4 MPa) and Rely X (51.6 MPa) showed higher DTS than that of self-cured groups (44.6...

Shear bond strength of resin cement bonded to alumina ceramic after treatment by aluminum oxide sandblasting or silica coating

Passos, Sheila Pestana; Valandro, Luiz Felipe; Bottino, Marco Antonio; Santos, Maria Jacinta Moraes Coelho; Santos Jr., Gildo Coelho
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 561-565
ENG
Relevância na Pesquisa
86.43%
Purpose: To evaluate the shear bond strength and bond durability between a dual-cured resin cement (RC) and a high alumina ceramic (In-Ceram Alumina), subjected to two surface treatments. Materials and Methods: Forty disc-shaped specimens (sp) (4-mm diameter, 5-mm thick) were fabricated from In-Ceram Alumina and divided into two groups (n = 20) in accordance with surface treatment: (1) sandblasting by aluminum oxide particles (50 μm Al 2O 3) (SB) and (2) silica coating (30 μm SiO x) using the CoJet system (SC). After the 40 sp were bonded to the dual-cured RC, they were stored in distilled water at 37°C for 24 hours. After this period, the sp from each group were divided into two conditions of storage (n = 10): (a) 24 h-shear bond test 24 hours after cementation; (b) Aging-thermocycling (TC) (12,000 times, 5 to 55°C) and water storage (150 days). The shear test was performed in a universal test machine (1 mm/min). Results: ANOVA and Tukey (5%) tests noted no statistically significant difference in the bond strength values between the two surface treatments (p= 0.7897). The bond strengths (MPa) for both surface treatments reduced significantly after aging (SB-24: 8.2 ± 4.6; SB-Aging: 3.7 ± 2.5; SC-24: 8.6 ± 2.2; SC-Aging: 3.5 ± 3.1). Conclusion: Surface conditioning using airborne particle abrasion with either 50 μm alumina or 30 μm silica particles exhibited similar bond strength values and decreased after long-term TC and water storage for both methods. © 2011 by The American College of Prosthodontists.

Effect of ceramic shade on the degree of conversion of a dual-cure resin cement analyzed by FTIR

Passos, Sheila P.; Kimpara, Estevão Tomomitsu; Bottino, Marco A.; Santos, Gildo C.; Rizkalla, Amin S.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 317-323
ENG
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76.47%
Objectives: The aim of this research was to evaluate the degree of monomer conversion of different resin cement shades when photocured under different feldspathic ceramic shades. The photocuring time was also evaluated as well as the translucency of each ceramic shade. Methods: Three VITA VM7 ceramic shades (Base Dentin 0M1, Base Dentin 2M2 and Base Dentin 5M3) were used to determine the translucency percentage. A spectrophotometer MiniScan was used to measure the opacity percentage of each specimen (2-mm-thick) and then the translucency was calculated. To measure the degree of conversion (DC), the resin cement (Variolink II; A3 Yellow and transparent) specimens (thickness: 100 μm) were photocured under a ceramic block (2-mm-thick) for 20 or 40 s. Specimens photocured without the ceramic block were used as control. Sixteen groups (n = 3) were evaluated. Micro-ATR/FTIR spectrometry was used to evaluate the extent of polymerization of all specimens after 24 h. The %DC was calculated of experimentally polymerized versus maximally polymerized composite. Results: The translucency percentages of 0M1, 2M2 and 5M3 ceramics were 12.41 (1.02)%, 5.75 (1.91)% and 1.07 (0.03)%, respectively. The %DC of both resin cement shades cured under ceramic 5M3 was significantly lower than the other groups (p < 0.05). The %DC of 0M1 groups exhibited no significant difference from 2M2 groups (p > 0.05)...

Efeito do modo de ativação de cimentos resinosos duais sobre a cinetica de conversão, prolpriedades mecanicas, resistencia de união e geração de tensões; Effec of activation mode of dual-cured resin cements on polymerization kinetics, mechanical properties, bond strength and stress generation

Andre Luis Faria e Silva
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 15/07/2008 PT
Relevância na Pesquisa
76.52%
Durante os procedimentos de cimentação de restaurações indiretas e pinos intra-radiculares usando cimentos resinosos, a polimerização apropriada do cimento é essencial para o sucesso clínico da restauração. Entretanto, o potencial de polimerização dos componentes de ativação química e por luz de cimentos resinosos duais demonstra ser muito variável. Em adição, o rápido aumento da viscosidade causado pela fotoativação pode inibir a polimerização ativada quimicamente e reduzir o grau de conversão (GC) final. Assim, os objetivos deste estudo foram avaliar o efeito da fotoativação (ausência, imediata ou tardia) de três cimentos resinosos duais (Enforce, RelyX ARC e Panavia F) sobre: 1 - cinética de taxa de polimerização (Tp); 2 - resistência à tração diametral (RTD) e rigidez relativa (RR); 3 - tensão de contração de polimerização (TC); 4 - resistência máxima à tração (RMT) e 5 - resistência de união ao cisalhamento (RU). Para este último, o tempo do teste (10 minutos ou 24 horas) também foi avaliado. A fotoativação aumentou o GC para todos os cimentos resinosos. A ativação tardia melhorou o GC para o Enforce, reduziu para o RelyX ARC e para o Panavia F. Entretanto, este modo de ativação reduziu a Tp para todos os cimentos. O Panavia F apresentou a mais lenta reação de polimerização e os menores GC quando usado na ausência de fotoativação. O uso do ED Primer com este cimento aumentou o GC para todos os modos de ativação. A ausência de fotoativação reduziu a RTD apenas para o Panavia F. Para a fotoativação tardia...

Procedures for reducing the incompatibility between simplified-step adhesive systems and dual-cured resin cements = : Procedimentos para redução da incompatibilidade entre sistemas adesivos simplificados e cimentos resinosos de dupla ativação; Procedimentos para redução da incompatibilidade entre sistemas adesivos simplificados e cimentos resinosos de dupla ativação

Ariene Arcas Topal Paes Leme
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 17/12/2013 PT
Relevância na Pesquisa
86.52%
Neste estudo avaliou-se o efeito: (1) da adição de resina de troca aniônica (AER) a um cimento experimental, para reduzir a incompatibilidade entre sistemas adesivos simplificados e cimento resinoso de polimerização dupla, quando ativado quimicamente; (2) da aplicação de uma camada extra de adesivo entre o sistema adesivo simplificado e o cimento resinoso, na resistência da união, propriedades nanomecânicas da camada de cimento e micropermeabilidade na interface adesiva. Discos de resina composta foram cimentados com os sistemas adesivos ACE ALL Bond TE ([ACE] Bisco Inc.) e Scotchbond Universal ([SCU] 3M ESPE) ... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital.; This study evaluated the effect of: (1) adding anion exchange resin (AER) to an experimental resin cement aiming to reduce incompatibility between simplified-step adhesive systems and dual-cured resin cement when chemically activated; (2) the application of an extra adhesive resin layer between the simplified adhesive system and resin cement, on the microtensile bond strength, nanomechanical properties of the cement layer and micropermeability at the adhesive layer. Resin composite discs were luted with the adhesive systems ACE ALL Bond TE ([ACE] Bisco Inc.) and Scotchbond Universal ([SCU] 3M ESPE) ... Note: The complete abstract is available with the full electronic document.

Influence of energy density of different light sources on knoop hardness of a dual-cured resin cement

Piva,Evandro; Correr-Sobrinho,Lourenço; Sinhoreti,Mario Alexandre Coelho; Consani,Simonides; Demarco,Flávio Fernando; Powers,John Michael
Fonte: Faculdade De Odontologia De Bauru - USP Publicador: Faculdade De Odontologia De Bauru - USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2008 EN
Relevância na Pesquisa
86.48%
The purpose of this study was to evaluate the Knoop hardness of a dual-cured resin-based luting cement irradiated with different light sources as well energy density through a ceramic sample. Three light-curing unit (LCUs) were tested: tungsten halogen light (HAL), light-emitting diode (LED) and xenon plasma-arc (PAC) lamp. Disc-shaped specimens were fabricated from a resin-based cement (Enforce). Three energy doses were used by modifying the irradiance (I) of each LCU and the irradiation time (T): 24 Jcm-2 (I/2x2T), 24 Jcm-2 (IxT) and 48 Jcm-2 (Ix2T). Energy doses were applied through a 2.0-mm-thick ceramic sample (Duceram Plus). Three groups underwent direct irradiation over the resin cement with the different LCUs and a chemically-activated group served as a control. Thirteen groups were tested (n=10). Knoop hardness number (KHN) means were obtained from cross-sectional areas. Two-way ANOVA and the Holm-Sidak method were used for statistical comparisons of activation mode and energy doses (a=5%). Application of 48 J.cm-2 energy dose through the ceramic using LED (50.5±2.8) and HAL (50.9±3.7) produced significantly higher KHN means (p<0.05) than the control (44.7±3.8). LED showed statistically similar performance to HAL. Only HAL showed a relationship between the increase of LCU energy dose and hardness increase.

Do blood contamination and haemostatic agents affect microtensile bond strength of dual cured resin cement to dentin?

KiLiC,Kerem; ARSLAN,Soley; DEMETOGLU,Goknil Alkan; ZARARSIZ,Gokmen; KESiM,Bulent
Fonte: Faculdade De Odontologia De Bauru - USP Publicador: Faculdade De Odontologia De Bauru - USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2013 EN
Relevância na Pesquisa
86.4%
Objective The purpose of this study was to evaluate the effects of blood contamination and haemostatic agents such as Ankaferd Blood Stopper (ABS) and hydrogen peroxide (H2O2) on the microtensile bond strength between dual cured resin cement-dentin interface. Material and Methods Twelve pressed lithium disilicate glass ceramics were luted to flat occlusal dentin surfaces with Panavia F under the following conditions: Control Group: no contamination, Group Blood: blood contamination, Group ABS: ABS contamination Group H2O2: H2O2 contamination. The specimens were sectioned to the beams and microtensile testing was carried out. Failure modes were classified under stereomicroscope. Two specimens were randomly selected from each group, and SEM analyses were performed. Results There were significant differences in microtensile bond strengths (µTBS) between the control and blood-contaminated groups (p<0.05), whereas there were no significant differences found between the control and the other groups (p>0.05). Conclusions Contamination by blood of dentin surface prior to bonding reduced the bond strength between resin cement and the dentin. Ankaferd Blood Stoper and H2O2 could be used safely as blood stopping agents during cementation of all-ceramics to dentin to prevent bond failure due to blood contamination.

Effect of immediate and delayed light activation on the mechanical properties and degree of conversion in dual-cured resin cements

Faria e Silva, Andr?? Luis; Piva, Evandro; Lima, Giana da Silveira; Boaro, Let??cia C.; Braga, Roberto R.; Martins, Luis R. M.
Fonte: Nihon University School of Dentistry Publicador: Nihon University School of Dentistry
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
86.45%
Abstract: We evaluated the effect of activation mode (immediate or delayed light activation vs. no light activation) on diametral tensile strength (DTS), elastic modulus, ultimate tensile strength (UTS), and degree of conversion (DC) in dual-cured resin cements. Three resin cements were evaluated: Enforce, RelyX ARC, and Panavia F. The mixed cements were inserted into circular molds for the DTS test and into dumbbell-shaped molds for the UTS test. Inside the molds, the cements were light-activated either immediately or after 5 min (delayed light activation). If no light activation was performed, the materials were protected from light exposure (control). The DTS and UTS tests were performed until fracture. The elastic modulus was calculated using data from the DTS test, and DC was evaluated 24 h after manipulation using near-infrared spectroscopy. Data for each variable were individually analyzed by two-way ANOVA and the post-hoc Tukey test (?? = 0.05). Regarding DTS, activation mode influenced only Panavia F specimens, which had the lowest DTS values in the absence of light activation. Activation mode did not influence the elastic modulus or UTS of any resin cement evaluated. Immediate light activation yielded higher DC values as compared with the absence of light activation. (Journal of Oral Science 54...

Influence of energy density of different light sources on knoop hardness of a dual cured resin cement

Piva, Evandro; Correr Sobrinho, Louren??o; Sinhoreti, M??rio Alexandre Coelho; Consoni, Simonides; Demarco, Fl??vio Fernando; Powers, John Michel
Fonte: University of S??o Paulo Publicador: University of S??o Paulo
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
86.48%
The purpose of this study was to evaluate the Knoop hardness of a dual-cured resin-based luting cement irradiated withdifferent light sources as well energy density through a ceramic sample. Three light-curing unit (LCUs) were tested: tungsten halogen light (HAL), light-emitting diode (LED) and xenon plasma-arc (PAC) lamp. Disc-shaped specimens were fabricated from a resin-based cement (Enforce). Three energy doses were used by modifying the irradiance (I) of each LCU and the irradiation time (T): 24 Jcm-2 (I/2x2T), 24 Jcm-2 (IxT) and 48 Jcm-2 (Ix2T). Energy doses were applied through a 2.0-mm-thick ceramic sample (Duceram Plus). Three groups underwent direct irradiation over the resin cement with the different LCUs and a chemically-activated group served as a control. Thirteen groups were tested (n=10). Knoop hardness number (KHN) means were obtained from cross-sectional areas. Two-way ANOVA and the Holm-Sidak method were used for statistical comparisons of activation mode and energy doses (??=5%). Application of 48 J.cm-2 energy dose through the ceramic using LED (50.5??2.8)and HAL (50.9??3.7) produced significantly higher KHN means (p<0.05) than the control (44.7??3.8). LED showed statistically similar performance to HAL. Only HAL showed a relationship between the increase of LCU energy dose and hardness increase.

The Influence of a Translucent Fiberglass Post on the Polymerization of Dual Cure Resin Cement Analyzed by Electron Paramagnetic Resonance

Salomão,Fabio Martins; Vicentin,Bruno Luiz Santana; Contreras,Edwin Fernando Ruiz; Hoeppner,Márcio Grama; Di Mauro,Eduardo
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2015 EN
Relevância na Pesquisa
76.47%
AbstractElectron Paramagnetic Resonance (EPR) was used as an alternative method to study the conversion degree of dual cure resin cement and verify the influence of prefabricated translucent fiberglass post on the dual cure resin cement polymerization at different restoration points. The post cementation of White Post DC (FGM, Joinville, SC, Brasil) was simulated using the dual cured resin cement Allcem (FGM, Joinville, SC, Brasil) in three different protocols: cement irradiated for 40 s; no light irradiation and cement irradiated with sealed cementation line. 2mm samples were obtained from three post sections and EPR spectra were obtained 10 minutes and 24 hours after mixing the base paste and catalyst of the cement. Results shows that the light curing protocol influenced the concentration of free radicals up to 8mm of the restoration, and the capacity of light transmission of the post was significant for the first 8mm of restoration and is non-existent in the deepest points of a simulated root canal. The cure in the apical part of restoration is exclusively chemical.

Influencia do metodo de fotoativação e materiais restauradores indiretos sobre o grau de conversão e dureza Knoop de um cimento resinoso dual; The influence of light curing and indirect restorative materials on conversion degree and Knoop hardness of dual-cured resin cement

Paula Carolina de Paiva Komori
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 09/12/2008 PT
Relevância na Pesquisa
96.65%
Os cimentos resinosos têm sido amplamente utilizados devido à capacidade de união ao dente e a prótese fixa e ao sucesso estético. Os cimentos resinosos apresentam ativação química, física ou dupla ativação. Para esses cimentos, quanto maior o grau de polimerização melhores serão suas propriedades. Entretanto, em diversas situações clínicas a polimerização é afetada pela distância da ponta da unidade fotoativadora em relação ao cimento, pela presença de restaurações indiretas ou estrutura dentária. Assim, este estudo avaliou a polimerização de um cimento resinoso de dupla ativação RelyX ARC (RLX), sob diferentes condições. No primeiro estudo para simular uma restauração indireta foram confeccionados discos com 1,4mm de espessura e 8mm de diâmetro das cerâmicas Empress 2 (EMP) e Empress Esthetic (EST), Duceram Plus (DUC) e resina composta Z250 (Z250). Amostras do RLX com 0,8mm de espessura e 5mm de diâmetro, foram fotoativadas diretamente e indiretamente sob o anteparo, com os aparelhos de fotoativação com lâmpada halógena (QTH - 800mW/cm2) e por diodo emissor de luz (LED - 1100mW/cm2). A potência (mW) das fontes de luz foram medidas com um potenciômetro (Ophir) e o espectro da luz emitida foi registrado com espectrômetro (USB 2000)...

Effect of thickness of indirect restoration and distance from the light-curing unit tip on the hardness of a dual-cured resin cement

Paula,Andréia Bolzan de; Tango,Rubens Nisie; Sinhoreti,Mário Alexandre Coelho; Alves,Marcelo Corrêa; Puppin-Rontani,Regina M.
Fonte: Fundação Odontológica de Ribeirão Preto Publicador: Fundação Odontológica de Ribeirão Preto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 EN
Relevância na Pesquisa
96.57%
This study evaluated the Knoop hardness and polymerization depth of a dual-cured resin cement, light-activated at different distances through different thicknesses of composite resin. One bovine incisor was embedded in resin and its buccal surface was flattened. Dentin was covered with PVC film where a mold (0.8-mm-thick and 5 mm diameter) was filled with cement and covered with another PVC film. Light curing (40 s) was carried out through resin discs (2, 3, 4 or 5 mm) with a halogen light positioned 0, 1, 2 or 3 mm from the resin surface. After storage, specimens were sectioned for hardness measurements (top, center, and bottom). Data were subjected to split-plot ANOVA and Tukey's test (a=0.05). The increase in resin disc thickness decreased cement hardness. The increase in the distance of the light-curing tip decreased hardness at the top region. Specimens showed the lowest hardness values at the bottom, and the highest at the center. Resin cement hardness was influenced by the thickness of the indirect restoration and by the distance between the light-curing unit tip and the resin cement surface.

Effect of curing mode on the hardness of dual-cured composite resin core build-up materials

Arrais,César Augusto Galvão; Kasaz,Aline de Cerqueira; Albino,Luís Gustavo Barrote; Rodrigues,José Augusto; Reis,Andre Figueiredo
Fonte: Sociedade Brasileira de Pesquisa Odontológica - SBPqO Publicador: Sociedade Brasileira de Pesquisa Odontológica - SBPqO
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2010 EN
Relevância na Pesquisa
76.75%
This study evaluated the Knoop Hardness (KHN) values of two dual-cured composite resin core build-up materials and one resin cement exposed to different curing conditions. Two dual-cured core build-up composite resins (LuxaCore®-Dual, DMG; and FluoroCore®2, Dentsply Caulk), and one dual-cured resin cement (Rely X ARC, 3M ESPE) were used in the present study. The composite materials were placed into a cylindrical matrix (2 mm in height and 3 mm in diameter), and the specimens thus produced were either light-activated for 40 s (Optilux 501, Demetron Kerr) or were allowed to self-cure for 10 min in the dark (n = 5). All specimens were then stored in humidity at 37°C for 24 h in the dark and were subjected to KHN analysis. The results were submitted to 2-way ANOVA and Tukey's post-hoc test at a pre-set alpha of 5%. All the light-activated groups exhibited higher KHN values than the self-cured ones (p = 0.00001), regardless of product. Among the self-cured groups, both composite resin core build-up materials showed higher KHN values than the dual-cured resin cement (p = 0.00001). LuxaCore®-Dual exhibited higher KHN values than FluoroCore®2 (p = 0.00001) when they were allowed to self-cure, while no significant differences in KHN values were observed among the light-activated products. The results suggest that dual-cured composite resin core build-up materials may be more reliable than dual-cured resin cements when curing light is not available.

The effect of viscosity and activation mode on biaxial flexure strength and modulus of dual resin cements

Francescantonio,Marina Di; Rueggeberg,Frederick Allen; Arrais,Cesar Augusto Galvão; Ambrosano,Glaucia Maria Bovi; Giannini,Marcelo
Fonte: Pontifícia Universidade Católica do Rio Grande do Sul Publicador: Pontifícia Universidade Católica do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2012 EN
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PURPOSE: The aim of this study was to evaluate the effects of curing mode and viscosity on the biaxial flexural strength (FS) and modulus (FM) of dual resin cements. METHODS: Eight experimental groups were created (n=12) according to the dual-cured resin cements (Nexus 2/Kerr Corp. and Variolink II/IvoclarVivadent), curing modes (dual or self-cure), and viscosities (low and high). Forty-eight cement discs of each product (0.5 mm thick by 6.0 mm diameter) were fabricated. Half specimens were light - activated for 40 seconds and half were allowed to self-cure. After 10 days, the biaxial flexure test was performed using a universal testing machine (1.27 mm/min, Instron 5844). Data were statistically analyzed by three-way ANOVA and Tukey's test (5%). RESULTS: Light-activation increased FS and FM of resin cements at both viscosities in comparison with self-curing mode. The high viscosity version of light-activated resin cements exhibited higher FS than low viscosity versions. The viscosity of resin and the type of cement did not influence the FM. Light-activation of dual-polymerizing resin cements provided higher FS and FM for both resin cements and viscosities. CONCLUSION: The use of different resin cements with different viscosities may change the biomechanical behavior of these luting materials.

Effect of light-curing methods on resin cement knoop hardness at different depths

Sinhoreti,Mário Alexandre Coelho; Manetta,Izabella Paola; Tango,Rubens Nisie; Iriyama,Nelson Tetsu; Consani,Rafael Leonardo Xediek; Correr-Sobrinho,Lourenço
Fonte: Fundação Odontológica de Ribeirão Preto Publicador: Fundação Odontológica de Ribeirão Preto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2007 EN
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This study evaluated, using Knoop hardness test, the polymerization depth of Rely-X dual-cured resin cement activated by chemical reaction alone (control group) or by chemical/physical mode with light curing through a 1.5-mm-thick ceramic layer (HeraCeram). Bovine incisors had their buccal surface flattened and hybridized. On this surface, a rubber mould (5 mm diameter; 1 mm high) was bulk filled with cement. Either a polyester strip or a 1.5-mm-thick disc of the veneering material was seated over this set. Light curing was performed with either conventional halogen light (QTH; XL2500) for 40 s, light-emitting diode (LED; Ultrablue Is) for 40 s or xenon plasma arc (PAC; Apollo 95E) for 3 s. In a control group, cement setting occurred by chemical reaction alone. After storage dry in dark (24 h/37ºC), the specimens (n=5) were sectioned for hardness (KHN) measurements at three depths in a microhardness tester (50 gf load/15 s). Data were submitted to ANOVA and Tukey's test (a = 0.05). Rely-X cement presented higher Knoop hardness values when the QTH and LED LCUs were used, compared to the control group and PAC. Light curing with PAC resulted in lower hardness compared to the control group. Cement hardness was significantly lower in deeper regions.

Influence of energy density of different light sources on knoop hardness of a dual-cured resin cement

Piva, Evandro; Correr-Sobrinho, Lourenço; Sinhoreti, Mario Alexandre Coelho; Consani, Simonides; Demarco, Flávio Fernando; Powers, John Michael
Fonte: Universidade de São Paulo. Faculdade de Odontologia de Bauru Publicador: Universidade de São Paulo. Faculdade de Odontologia de Bauru
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; Formato: application/pdf
Publicado em 01/06/2008 ENG
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The purpose of this study was to evaluate the Knoop hardness of a dual-cured resin-based luting cement irradiated with different light sources as well energy density through a ceramic sample. Three light-curing unit (LCUs) were tested: tungsten halogen light (HAL), light-emitting diode (LED) and xenon plasma-arc (PAC) lamp. Disc-shaped specimens were fabricated from a resin-based cement (Enforce). Three energy doses were used by modifying the irradiance (I) of each LCU and the irradiation time (T): 24 Jcm-2 (I/2x2T), 24 Jcm-2 (IxT) and 48 Jcm-2 (Ix2T). Energy doses were applied through a 2.0-mm-thick ceramic sample (Duceram Plus). Three groups underwent direct irradiation over the resin cement with the different LCUs and a chemically-activated group served as a control. Thirteen groups were tested (n=10). Knoop hardness number (KHN) means were obtained from cross-sectional areas. Two-way ANOVA and the Holm-Sidak method were used for statistical comparisons of activation mode and energy doses (a=5%). Application of 48 J.cm-2 energy dose through the ceramic using LED (50.5±2.8) and HAL (50.9±3.7) produced significantly higher KHN means (p

Do blood contamination and haemostatic agents affect microtensile bond strength of dual cured resin cement to dentin?

KiLiC, Kerem; ARSLAN, Soley; DEMETOGLU, Goknil Alkan; ZARARSIZ, Gokmen; KESiM, Bulent
Fonte: Universidade de São Paulo. Faculdade de Odontologia de Bauru Publicador: Universidade de São Paulo. Faculdade de Odontologia de Bauru
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; Formato: application/pdf
Publicado em 01/01/2013 ENG
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Objective The purpose of this study was to evaluate the effects of blood contamination and haemostatic agents such as Ankaferd Blood Stopper (ABS) and hydrogen peroxide (H2O2) on the microtensile bond strength between dual cured resin cement-dentin interface. Material and Methods Twelve pressed lithium disilicate glass ceramics were luted to flat occlusal dentin surfaces with Panavia F under the following conditions: Control Group: no contamination, Group Blood: blood contamination, Group ABS: ABS contamination Group H2O2: H2O2 contamination. The specimens were sectioned to the beams and microtensile testing was carried out. Failure modes were classified under stereomicroscope. Two specimens were randomly selected from each group, and SEM analyses were performed. Results There were significant differences in microtensile bond strengths (µTBS) between the control and blood-contaminated groups (p<0.05), whereas there were no significant differences found between the control and the other groups (p>0.05). Conclusions Contamination by blood of dentin surface prior to bonding reduced the bond strength between resin cement and the dentin. Ankaferd Blood Stoper and H2O2 could be used safely as blood stopping agents during cementation of all-ceramics to dentin to prevent bond failure due to blood contamination.