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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Evaluation of water sorption and solubility behavior of nine different polymeric luting materials

Alsheikh, Rasha N. January 2009 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The cementation procedure is the key to long-term success of fixed restorations. The prognosis of prosthetic restoration is largely impacted by the maintenance of the luting cement and the adhesive bond. When exposed to water or saliva, most restorative materials undergo hydrolytic degradation. The purpose of this study is to evaluate the water solubility and water sorption characteristics of newly introduced acidic polymeric luting agents over a 180-day water-storage period. Nine different luting agents were tested. Fifty-two disc specimens of each material were fabricated using a mold with an internal dimension of 15[plus-minus]0.1 mm in diameter and 1.0 [plus-minus]0.1 mm deep. A constant weight, W0 [subscript zero], was reached after desiccating the specimens. Then, 13 specimens were assigned randomly to one of the four testing periods in the water for seven, 30, 90 and 180 days. After each period, the specimens were removed from the water and weighed to get W1 [subscript one]. A second period of desiccating the samples provided a constant weight W2 [subscript two]. The water sorption and solubility were determined by the following equations: WSP [subscript SP](%) = (W1 [subscript one] W2 [subscript two] ) X 100/ W0 [subscript zero] ,WSL [subscript SL](%) = (W0 [subscript zero] W2 [subscript two) X 100/ W0 [subscript zero]. The resin-modified glass-ionomers showed the highest water sorption/solubility results. The resin luting agents had the lowest sorption/solubility results. The self-adhesives showed a wide range of solubility/sorption; in general, they showed lower results compared with the resin-modified glass-ionomers. All the materials reached some sort of equilibrium after 90-days. Based on the results of our study, we conclude that self-adhesive luting materials were not all alike. Rely X Unicem was the most comparable to the resin luting materials. The resin luting materials had the lowest solubility and sorption. Resin-modified glass-ionomers showed the highest sorption/solubility results.
112

The effect of filler on the mechanical properties of a novel resin-based calcium phosphate cement

Al Dehailan, Laila January 2010 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Several studies have found that resin-based amorphous calcium phosphate (ACP) composites can function well for applications that do not require high mechanical demand. Milled tricalcium phosphate (TCP), a new calcium-phosphate-releasing material, is crystalline in nature, suggesting it to be strong. In the present study, we investigated the use of a TCP-filled composite resin as a possible tooth restorative-material. An experimental TCP-based composite was prepared using monomer with a mixture of 34.3 percent by mass of EBPADMA, 34.2 percent by mass of HmDMA, and 30.5 percent by mass of HEMA. TCP fillers were added to the monomer mixture at different levels (30 percent, 40 percent, 50 percent, and 60 percent by weight). A universal testing machine (Sintech Renew 1121; Instron Engineering Corp., Canton, MA) was used to measure the compressive strength and modulus. FTIR was used to measure the degree of conversion. The depth of cure was determined according to the ISO standards for dental resin 4049 using the scrapping technique. Knoop hardness numbers were obtained by a microhardness tester (M-400; Leco Co., St. Joseph, MI). The viscosities of the experimental resin were determined in a viscometer (DV-II+ Viscometer; Brookfield, Middleboro, MA). The data were analyzed using a one-way analysis of variance (ANOVA). A 5-percent significance level was used for all the tests. Resin composites with 30-percent TCP filler showed the highest compressive strength and hardness values. Also, this group showed the lowest degree of conversion. Resin composites with 60-percent TCP filler showed the highest degree of conversion. However, this group showed the lowest compressive strength, depth of cure, and hardness. Resin composites with 50-percent filler showed the highest compressive modulus. Resin composites with 40-percent filler showed higher viscosity values than resin composites with 30-percent filler. In conclusion, increasing the filler level significantly reduced the compressive strength, hardness, and depth of cure, but increased the degree of conversion. Also, resin composites with the lowest filler level (30 percent) had the highest compressive strength, depth of cure, and hardness. From these results, it can be concluded that the experimental TCP-filled resin used in this study cannot be used as restorative material.
113

Microleakage in new resin-modified glass ionomer cements using new no-rinse conditioners : an in-vitro study

Patel, Ashish G. January 2012 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Since their introduction in 1970, glass ionomer cements have been used in a wide variety of clinical situations in dentistry. The main advantages of glass ionomer cements are chemical bonding, fluoride release and uptake, excellent seal against microleakage, and biocompatibility. The main objective of this study was to compare the microleakage of two new paste-paste glass ionomer systems to their traditional RMGIC counterparts when conditioning the dentin with newly developed no-rinse conditioners or polyacrylic acid. Materials and methods: Standardized cavity preparations were made, centered on the cementoenamel junction of the buccal surface, on 96 extracted human molars divided in 8 groups (n = 12). G1 Ketac Nano with Ketac Nano Primer, G2 Ketac Nano with Ketac Conditioner, G3 Photac Fil with Ketac Nano Primer, G4 Photac Fil with Ketac Cavity Conditioner, G5 Fuji Filling LC with GC Self Conditioner, G6 Fuji Filling LC with GC Cavity Conditioner, G7 Fuji II LC with GC Self Conditioner, G8 Fuji II LC with GC Cavity Conditioner. The cavities were treated with either a no-rinse or polyacrylic acid conditioner and restored with a paste-paste RMGIC or traditional RMGIC from the same manufacturer (n =12). The teeth were then sealed to within 2 mm of the restoration margins and thermocycled. The teeth were immersed in 2.0-percent methylene blue and stored at room temperature for 24 hours. Then, the teeth were be embedded in resin and sectioned longitudinally in a buccolingual direction making 1 section (1 mm thick) per tooth. The occlusal and gingival restoration margins of each specimen were examined with a stereomicroscope at X10 magnification to determine the degree of microleakage. Results: Mixed-model ANOVA was used to test the fixed effect of the eight groups and cervical vs. occlusal location within each tooth sample on microleakage, with sample as the random effect. Both main effects and the interaction are significant, p < 0001 for both group and location effects, and p = 0.0013 for the interaction of group and location. The cervical interface showed more microleakage in all groups except group 8 where microleakage was the same as at the occlusal margin. No significant difference was observed among groups for microleakage at the occlusal interface. There was significant difference among groups at the cervical interface with Fuji II LC using GC Cavity Conditioner performing best. For the occlusal interface Group 4 performed the best and Group 2 performed the worst, although the difference was not significant among the groups. For the cervical interface, Group 8 performed the best followed by Group 3, Group 4 and Group 6, although these four groups were not significantly different. For the cervical interface, group 2 performed the worst followed by group 1. Based on these results we can conclude that, overall, traditional RMGIC with polyacrylic acid conditioning performed better than the new paste-paste RMGIC systems utilizing the no-rinse conditioners.
114

Influência dos cimentos resinosos e sistemas cerâmicos na translucidez e estabilidade de cor de restaurações laminadas / Influence of resin cements luting and ceramic systems in the translucency and color stability of veneers

Silami, Francisca Daniele Jardilino 31 March 2017 (has links)
O objetivo desse estudo foi avaliar o grau de conversão, a estabilidade de cor e translucidez de cimentos resinosos para cimentação de laminados cerâmicos em duas espessuras, submetidos a diferentes protocolos de envelhecimento. Foram utilizados 270 incisivos bovinos hígidos, cujas porções radiculares foram cortadas e as porções coronárias foram incluídas em matriz de PVC (25mm de diâmetro) com resina acrílica. As faces vestibulares foram planificadas até a dentina. Foram confeccionados 240 corpos-de-prova em cerâmica prensada (IPS e-max Press e IPS e- maxZirpress, IvoclarVivadent), em duas espessuras (0,5 mm e 1,0 mm), que foram separados aleatoriamente em dois grupos, segundo o tipo de cimento resinoso utilizado para fixação: fotoativado (Variolink II, Ivoclar/Vivadent) ou dual (Rely U 200, 3M ESPE). Após a cimentação, todas as amostras foram mantidas em estufa a 37°C por 24h, após o qual foram realizadas as leituras de cor e translucidez iniciais (Vita EasyShade, VITA). Em seguida, as amostras foram subdivididas em três grupos (n=10) de acordo com o envelhecimento a que foram submetidos: Controle sem envelhecimento; imersão em água destilada por 1 ano e fadiga termomecânica (1.200.000 ciclos, frequência de1,3Hz e ciclagem térmica de 5°C/37°C/55°C). Como controle, foram obtidos 30 corpos-de-prova de cada cimento resinoso (0,5mm) e 30 dentes foram planificados e submetidos aos mesmos processos de envelhecimento, após o qual leituras finais foram realizadas. Foram analisados também o grau de conversão dos cimentos polimerizados através das restaurações (FTIR) e a linha de cimentação em cada um dos grupos (n=3), antes e depois do envelhecimento. Para isso, as amostras, selecionadas aleatoriamente, foram seccionadas no sentido longitudinal e analisadas em estereomicroscópio de dupla coordenada (Nikon Measurescope). Os dados de estabilidade de cor (&Delta;E), translucidez, grau de conversão e linha de cimentação foram submetidas à análise estatística (3-way ANOVA, Tukey, p<0,05). O cimento autoadesivo apresentou maior grau de conversão que o fotoativado (p<0,05) quando utilizada a cerâmica Zirpress, mas produziu maior alteração de cor (p<0,05) e menor translucidez nas restaurações de E-maxPress de 0,5mm. A ciclagem termomecânica não foi significante para alterações óticas dos sistemas cerâmicos testados. Conclui-se que a espessura do laminado cerâmico não altera o grau de conversão dos cimentos resinosos e o tipo de cimento resinoso influencia a estabilidade de cor das restaurações cerâmicas quando submetido ao envelhecimento com água destilada. / The aim of this study is to evaluate the degree of conversion, color stability and translucency of resin cement for luting ceramic veneers with two thicknesses submitted to different aging protocols. Two hundred and seventy bovine incisors were used, which had the root cut, and the coronal were embedded in acrylic resin into PVC rings (25mm diameter). The buccal surface was flattened until dentin. Two hundred and forty pressed ceramic veneers (IPS e-max Press and IPS e-max ZirPress, IvoclarVivadent) were obtained, in two thicknesses (0,5 mm and 1.0 mm), that were randomly separated into two groups according to the type of resin cement used for luting: light-cured (Variolink II, Ivoclar / Vivadent) or dual cured (Rely U 200, 3M ESPE). After the cementation, all samples were maintained at 37 °C for 24 h; after first color and translucency readings (Vita EasyShade, VITA) were made. The samples were separated into 3 groups (n=10) according to the aging that was submitted: control without aging, immersion in distilled water for one year and thermomechanical cycling (1.200.000 cycles, frequency of 1,3Hz and thermal cycling of 5°C/37°C/55°C). As the control group, 30 samples of each resin cement (0,5 mm) and flattened teeth were obtained and submitted to the same aging protocols. After tests, the final color and translucency readings were taken. The degree of conversion of resin cements through veneer restoration, and the cement film thickness (n=3) for each group were analyzed (FTIR), before and after aging. For this, the samples were randomly selected, sectioned longitudinally and examined by a stereomicroscope (Nikon Measurescope). The results of color stability (&Delta;E), translucency, degree of conversion and cement film thicknesses were statistically analyzed (3-way, ANOVA, Tukey, p<0.05). The self-adhesive cement showed the higher degree of conversion than light-activated luting cement (p<0.05) when Zirpress ceramic was used, but produced higher color change (p<0.05) and lower translucency in 0.5mm E-maxPress restorations. The thermomechanical cycling was not significant for optical changes of tested ceramic systems. It was concluded that the thickness of ceramic veneers didnt alter the degree of conversion of resin cement and the type of resin cement has influenced the color stability of ceramic restorations when submitted to water aging.
115

Resistência de união de um cimento resinoso a diferentes superfícies de alumina densamente sinterizada / Shear bond strenght of a resin cement to different surfaces of densely sintered alumina

Valdivia, Juan Rommel Medina 20 June 2007 (has links)
O propósito deste estudo foi avaliar a resistência adesiva ao cisalhamento de um cimento resinoso à alumina densamente sinterizada testando o tratamento superficial feito pelo fabricante. O cimento utilizado foi o Multilink (Ivoclar Vivadent) e a alumina foi a Procera®Alumina (Nobel Biocare) constituída por 99,9 % de óxido de alumínio densamente sinterizado. Trinta e dois cilindros de alumina foram confeccionados pela Nobel Biocare, onde um dos extremos deste cilindro recebeu o tratamento superficial e o outro não. Para a aplicação do cimento resinoso sobre os cilindros de alumina, utilizou-se uma matriz de Teflon com um orifício central de 3,5mm de diâmetro por 3,0mm de profundidade. Foram determinados 4 grupos experimentais: Grupo 1 superfície sem tratamento; Grupo 2 superfície sem tratamento e com aplicação de adesivo; Grupo 3 - superfície com o tratamento realizado pelo fabricante; Grupo 4 superfície com tratamento realizado pelo fabricante e com adesivo. Após a aplicação do cimento nos 4 grupos, os espécimes foram armazenados em água deionizada a 37ºC durante 24h, sendo, em seguida, montados em uma máquina universal de ensaios para realização dos testes de resistência ao cisalhamento. Os resultados foram submetidos à análise de variância a dois critérios e ao teste de Tukey para comparação entre os grupos. A superfície tratada (grupo 3) apresentou valores significativamente maiores que todos os outros grupos. A presença do adesivo diminuiu a resistência adesiva quando aplicado na superfície tratada, mas não deu diferença significante quando aplicado na superfície sem tratamento. / The aim of this study was to investigate the shear bond strength between a resin cement and densely sintered alumina treated by the fabricant. The resin cement used was the Multilink (Ivoclar Vivadent) and the alumina the Procera®Alumina (Nobel Biocare) made with 99,9% of densely sintered aluminum oxide. Thirty two alumina cylinders were made by Nobel Biocare, and in one of the extremes was applied a own`s fabricant surface treatment. For the application of the cement, a Teflon matrix with a central hole (diameter of 3,5 mm and a height of 3,0 mm) was used. Four groups were created: Group 1 surface without treatment; Group 2 - surface without treatment and with adhesive; Group 3 surface with the own`s fabricant treatment; Group 4 - surface with the own`s fabricant treatment with adhesive. After the cement application, the specimens were stored in water at 37º C for 24 hours. Then the samples were placed in a universal testing machine for making the shear strength test. Statistical analysis was performed with two-way analysis of variance (ANOVA), and paired comparisons between groups were done with Tukey`s multiple comparison. Higher significant values were detected for Group 3 when compared with all the other groups. The adhesive decreased the shear bond strength when laid on the treated surface, and there were no difference when laid on the untreated surface.
116

Avaliação in vitro do efeito do clareamento dental prévio a cimentação de restaurações indiretas / In vitro evaluation of the effect of dental bleaching prior to cementation of indirect restorations

Fogli, Silvia Stuber 05 June 2017 (has links)
O presente trabalho experimental, tem como objetivo avaliar \"in vitro\" possíveis falhas na cimentação de fragmentos cerâmicos sobre substrato de esmalte dentário previamente submetido ao clareamento dental e analisados pelo sistema de tomografia por coerência ótica. O ensaio experimental foi realizado in vitro, fazendo uso de trinta pré-molares superiores humanos. Cada elemento dental teve sua porção de esmalte vestibular aplainada por meio de disco de sílica na granulação 120, foram cimentados fragmentos cerâmicos retangulares de 1.5mm de espessura. Os dentes foram distribuídos aleatoriamente em 3 grupos de 10 dentes cada (n=10), Grupo 1: Fragmentos cimentados sem serem submetidos ao tratamento clareador; Grupo 2: Fragmentos cimentados 24 hrs. Após serem submetidos ao clareamento dental; Grupo 3: Fragmentos cimentados 7 dias após serem submetidos ao clareamento dental. Os espécimes foram transferidos para o sistema de tomografia por coerência óptica para seus respectivos monitoramentos após exposição ao agente clareador e cimentação da restauração indireta e ao final dos ensaios de envelhecimento artificial por termociclagem. A variável de resposta, falhas na interface esmalte e cimento resinoso, foi avaliada por escores (0,1 e 2) que representam em ordem crescente as falhas entre o substrato dental e a restauração indireta. Os valores obtidos foram analisados por meio de testes não paramétricos (Kruskal-Wallis e Wilcoxon). Os resultados constituíram de 60 escores de fendas referentes aos 3 grupos (G1;G2;G3) analisados imediatamente após a cimentação e após a termociclagem. A comparação entre os 3 grupos após termociclagem demonstrou haver diferença estatisticamente significante (p<0,0001) pela comparação dois a dois pelo teste complementar de Dunn e detectou-se que o G2 cimentado após 24 horas do clareamento apresentou mais fendas que G1 e G3. Com base nestes resultados e na metodologia utilizada pode-se concluir que, dentes submetidos ao tratamento clareador, o protocolo clinico de cimentação de restaurações cerâmicas indiretas, quando realizado 7 dias após o clareamento gerou menor quantidade de fendas na interface, propondo assim melhor qualidade na adaptação dente/restauração. / The present experimental study has the objective of evaluating in vitro possible failures in the cementation of ceramic fragments over dental enamel substrate previously submitted to dental bleaching and analyzed by optical coherence tomography system. The experimental trial was performed in vitro using thirty human maxillary premolars. Each dental element had have it\'s portion of vestibular enamel planed by a silic disk in granulation 120, ceramic fragments with a diameter of 1.5mm thickness were cemented. The teeth were randomly distributed in 3 groups of 10 teeth each (n = 10), Group 1: Bonded Veneer without being subjected to bleaching treatment Group 2: Bonded Veneer 24 hours after being submitted to dental bleaching Group 3: Bonded Veneer 7 days after being submitted to dental bleaching. The specimens were transferred to the optical coherence tomography system for their respective monitoring after being exposured to the whitening agent and cementation of the indirect restoration and at the end of the artificial aging tests by thermocycling. The variable of response, at faults in the interface enamel and resin cement, was evaluated by scores (0,1 and 2) that represent in increasing order the failures between dental substrate and indirect restoration. The values obtained were analyzed by non-parametric tests (Kruskal-Wallis and Wilcoxon). The results consisted of 60 gaps scores for the three groups (G1, G2, G3) analyzed immediately after bonding and after thermocycling. The comparison between the 3 groups after thermocycling, showed a statistically significant difference (p <0.0001) by the two-to-two comparison by Dunn\'s complementary test and it was detected that G2 after 24 hours of bleaching, showed more gaps than G1 and G3. Based on these results and the methodology used, it was concluded that, when teeth were submitted to the bleaching treatment, the clinical cementation protocol of indirect ceramic restorations, when performed 7 days after bleaching, generated fewer gaps at the interface, thus proposing a better quality in the relation Tooth / restoration.
117

Resistência à fratura de diferentes núcleos de preenchimento com compósitos bulk fill em dentes com extensa destruição coronária /

Oliveira, Carlos Rangel de Moura January 2019 (has links)
Orientador: José Maurício dos Santos Nunes Reis / Resumo: Este estudo objetivou avaliar a resistência máxima e o padrão de fratura de diferentestécnicas para núcleo preenchimento associados a pinos de fibra de vidro em incisivoslaterais inferiores bovinos com extensa destruição coronária. Quarenta dentes forampreparados endodonticamente, divididos aleatoriamente em 4 grupos experimentais(n=10) e um pino de fibra de vidro (Whitepost DC0,5) foi cimentado com LuxaCore Zpara todos os grupos. A confecção dos núcleos de preenchimento foi realizada, apósobtenção de férula cervical de 1,0 mm, com: FOBF-Filtek One Bulk Fill; FZ350- FiltekZ350 XT; FBFF-Filtek Bulk Fill Flow; e LCZ-LuxaCore Z. Coroas totais de zircônia (YTZP) produzidas em CAD/CAM foram cimentadas com RelyX U200. Apósarmazenamento em água destilada a 37°C por 48 h, os corpos-de-prova foramsubmetidos a ciclos térmicos (10.000 ciclos, 5-55ºC, banhos de 30s) e, posteriormente,ao ensaio mecânico de resistência à fratura por força compressiva aplicada (1,0mm/min) em 135º ao longo eixo do dente em máquina eletromecânica (EMIC DL2000).A força máxima suportada por cada espécime foi registrada em Newton. O modo defratura foi classificado por meio de análise em lupa estereomicroscópica (30X). Osdados de resistência à fratura foram analisados pelo teste não paramétrico de KruskalWallis, seguido pelo post-hoc teste de Dunn. Os dados dos padrões de fratura foramanalisados pelo teste exato de Fisher (α=0,05). Não foram observadas diferençassignificativas (p>0... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study aimed to evaluate the ultimate fracture strength and failure modes of different core techniques associated with intraradicular fiberpost in bovine mandibular lateral incisors with extensive coronary destruction. Forty teeth were prepared endodontically, randomly divided into 4 experimental groups (n=10) and a fiberpost (Whitepost DC0.5) was cemented with LuxaCore Z for all groups. The core was confeccioned, after obtaining a 1.0 mm cervical ferrule, with: FOBF-Filtek One Bulk Fill; FZ350- Filtek Z350 XT; FBFF-Filtek Bulk Fill Flow; and LCZ-LuxaCore Z. Total zirconia crowns (Y-TZP) produced by CAD/CAM were cemented with RelyX U200. After storage in distilled water at 37ºC for 48 h, the specimens were submitted to thermal cycling (10,000 cycles, 5- 55ºC, 30 s dwell time) and, afterwards, to the mechanical test of compressive strength fracture (1.0 mm / min) at 135º along the tooth axis in electromechanical machine (EMIC DL2000). The ultimate load supported by each specimen was recorded in Newton. The fracture mode was classified by means of stereomicroscopic loupe analysis (30X). The fracture strength data were analyzed by the non-parametric Kruskal-Wallis test, followed by the post-hoc Dunn test. The data of the fracture modes were analyzed by Fisher's exact test (α=0.05). No significant differences (p>0.05) were observed among the FOBF, FZ350 and FBFF groups (mean ranks= 20.30, 12.20 and 23.20, respectively). LCZ (mean rank= 26.30) produced similar results to those... (Complete abstract click electronic access below) / Mestre
118

Influência dos cimentos resinosos e sistemas cerâmicos na translucidez e estabilidade de cor de restaurações laminadas / Influence of resin cements luting and ceramic systems in the translucency and color stability of veneers

Francisca Daniele Jardilino Silami 31 March 2017 (has links)
O objetivo desse estudo foi avaliar o grau de conversão, a estabilidade de cor e translucidez de cimentos resinosos para cimentação de laminados cerâmicos em duas espessuras, submetidos a diferentes protocolos de envelhecimento. Foram utilizados 270 incisivos bovinos hígidos, cujas porções radiculares foram cortadas e as porções coronárias foram incluídas em matriz de PVC (25mm de diâmetro) com resina acrílica. As faces vestibulares foram planificadas até a dentina. Foram confeccionados 240 corpos-de-prova em cerâmica prensada (IPS e-max Press e IPS e- maxZirpress, IvoclarVivadent), em duas espessuras (0,5 mm e 1,0 mm), que foram separados aleatoriamente em dois grupos, segundo o tipo de cimento resinoso utilizado para fixação: fotoativado (Variolink II, Ivoclar/Vivadent) ou dual (Rely U 200, 3M ESPE). Após a cimentação, todas as amostras foram mantidas em estufa a 37°C por 24h, após o qual foram realizadas as leituras de cor e translucidez iniciais (Vita EasyShade, VITA). Em seguida, as amostras foram subdivididas em três grupos (n=10) de acordo com o envelhecimento a que foram submetidos: Controle sem envelhecimento; imersão em água destilada por 1 ano e fadiga termomecânica (1.200.000 ciclos, frequência de1,3Hz e ciclagem térmica de 5°C/37°C/55°C). Como controle, foram obtidos 30 corpos-de-prova de cada cimento resinoso (0,5mm) e 30 dentes foram planificados e submetidos aos mesmos processos de envelhecimento, após o qual leituras finais foram realizadas. Foram analisados também o grau de conversão dos cimentos polimerizados através das restaurações (FTIR) e a linha de cimentação em cada um dos grupos (n=3), antes e depois do envelhecimento. Para isso, as amostras, selecionadas aleatoriamente, foram seccionadas no sentido longitudinal e analisadas em estereomicroscópio de dupla coordenada (Nikon Measurescope). Os dados de estabilidade de cor (&Delta;E), translucidez, grau de conversão e linha de cimentação foram submetidas à análise estatística (3-way ANOVA, Tukey, p<0,05). O cimento autoadesivo apresentou maior grau de conversão que o fotoativado (p<0,05) quando utilizada a cerâmica Zirpress, mas produziu maior alteração de cor (p<0,05) e menor translucidez nas restaurações de E-maxPress de 0,5mm. A ciclagem termomecânica não foi significante para alterações óticas dos sistemas cerâmicos testados. Conclui-se que a espessura do laminado cerâmico não altera o grau de conversão dos cimentos resinosos e o tipo de cimento resinoso influencia a estabilidade de cor das restaurações cerâmicas quando submetido ao envelhecimento com água destilada. / The aim of this study is to evaluate the degree of conversion, color stability and translucency of resin cement for luting ceramic veneers with two thicknesses submitted to different aging protocols. Two hundred and seventy bovine incisors were used, which had the root cut, and the coronal were embedded in acrylic resin into PVC rings (25mm diameter). The buccal surface was flattened until dentin. Two hundred and forty pressed ceramic veneers (IPS e-max Press and IPS e-max ZirPress, IvoclarVivadent) were obtained, in two thicknesses (0,5 mm and 1.0 mm), that were randomly separated into two groups according to the type of resin cement used for luting: light-cured (Variolink II, Ivoclar / Vivadent) or dual cured (Rely U 200, 3M ESPE). After the cementation, all samples were maintained at 37 °C for 24 h; after first color and translucency readings (Vita EasyShade, VITA) were made. The samples were separated into 3 groups (n=10) according to the aging that was submitted: control without aging, immersion in distilled water for one year and thermomechanical cycling (1.200.000 cycles, frequency of 1,3Hz and thermal cycling of 5°C/37°C/55°C). As the control group, 30 samples of each resin cement (0,5 mm) and flattened teeth were obtained and submitted to the same aging protocols. After tests, the final color and translucency readings were taken. The degree of conversion of resin cements through veneer restoration, and the cement film thickness (n=3) for each group were analyzed (FTIR), before and after aging. For this, the samples were randomly selected, sectioned longitudinally and examined by a stereomicroscope (Nikon Measurescope). The results of color stability (&Delta;E), translucency, degree of conversion and cement film thicknesses were statistically analyzed (3-way, ANOVA, Tukey, p<0.05). The self-adhesive cement showed the higher degree of conversion than light-activated luting cement (p<0.05) when Zirpress ceramic was used, but produced higher color change (p<0.05) and lower translucency in 0.5mm E-maxPress restorations. The thermomechanical cycling was not significant for optical changes of tested ceramic systems. It was concluded that the thickness of ceramic veneers didnt alter the degree of conversion of resin cement and the type of resin cement has influenced the color stability of ceramic restorations when submitted to water aging.
119

AVALIAÇÃO DA ESTABILIDADE DE COR DE LAMINADOS CERÂMICOS APÓS CIMENTAÇÃO ADESIVA / Evaluation of color stability of ceramic veneers after adhesive cementation

Sakamoto Junior, Antonio Setsuo 22 December 2015 (has links)
Made available in DSpace on 2017-07-24T19:21:58Z (GMT). No. of bitstreams: 1 Antonio Setsuo Sakamoto Junior.pdf: 2373735 bytes, checksum: b35b9e1a804cb1e6e80c6137dada9016 (MD5) Previous issue date: 2015-12-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Thin ceramic laminates have been widely requested by patients because it’s a reliable conservative aesthetic procedure, stable and presents adequate longevity. It is known that the color change of the cement below these thin restorations may result inappropriate final color. Thus, the purpose of this in vitro study was to evaluate the color agreement between pressable lithium disilicate ceramics with tryin pastes and corresponding resin cements, determination of the degree of conversion of resin cements using FT-Raman spectroscopic and color stability after artificial accelerated aging (AAA) for 300 hours. Eighty-four ceramic discs (0.3 mm, 0.5 mm, 1.0 mm thick) were prepared (IPS e.maxPress HT A2 – Ivoclar Vivadent) to simulate veneers. Evaluation the baseline color was done in the CIE-L*a*b* color space with reflectance spectrophotometer (control group). The try-in pastes were applied into the interlayer of the ceramic (simulation of selection color procedure) above silicon transparent matrix (0.1 mm thick) and the color complex were measured using a spectrophotometer (n=7), with no substrate. The same ceramic discs were used for cementation procedure with Variolink II (only base),after storage in distilled water, protected from light, at 37ºC for 24 hours, the specimens were mensured the color and submitted to FT-Raman spectroscopy to determinate the degree of conversion (DC). After that, the specimens were AAA for 300 hours and measured by spectrophotometer to calculate ΔE. Two-way ANOVA was used to analyze the data. Tukey’s post hoc for multiple comparisons and Spearman correlation test were performed (α = 0.05). There was no agreement between the try-in with resin cements, L* and b* values increased, increasing the value/opacity,yellowish of the complex. All groups exhibited values of ΔE>3.3, except resin color A3 group (1.0 mm ceramic thickness). Ceramic thicknesses (0.3 mm and 0.5 mm) did not affect the DC compared to the control (p> 0.05). Thus, DC was influenced by the color of cement, where the over saturated color showed higher conversion rate, DC decreased when ceramic disc thickness increased. No correlation between DC and ΔE was observed. / A modalidade indireta de restauração denominada laminado cerâmico, vem sendo vastamente solicitada pelos pacientes, por se tratar de um procedimento confiável, estável, conservador, estético e apresenta longevidade aceitável. Sabe-se que a alteração de cor do cimento localizado abaixo destas restaurações delgadas pode influenciar negativamente no aspecto estético final. Desta forma, o propósito do presente estudo in vitro foi avaliar a concordância da coloração da pasta de prova e seu respectivo cimento resinoso, verificar o grau de conversão deste pelo método Micro-Raman e sua estabilidade de cor após envelhecimento artificial acelerado (EAA) por 300 horas. Foram confeccionados 84 discos cerâmicos com sistema IPS e.maxPress HT (Ivoclar Vivadent) na cor A2 com 3 espessuras (0.3 mm, 0.5 mm, 1.0 mm) cuja coloração foi mensurada com espectrofotometria de refletância (grupo controle). Em seguida, foi realizada a simulação da seleção da cor do cimento Variolink II (try in Transparente, Opaco, A3) e mensurada a cor do conjunto nas coordenadas CIEL* a*b*. Depois foi realizada a cimentação adesiva (mesmos discos cerâmicos utilizados com try in) com três cores de cimentos resinosos (Base: Transparente, Opaco, A3), sobre uma matriz de silicone transparente com cavidade de espessura de 0,1 mm (n=7), sem qualquer substrato. Após armazenamento com água destilada, protegido da luz, em estufa a 37ºC por 24h, os corpos de prova (cp) foram submetidos novamente ao teste de espectrofotometria e ao teste grau de conversão (GC) pelo método FT-Raman. Em seguida, foram submetidos ao EAA por 300 horas e mensurada a coloração para verificar se houve alteração (ΔE). Os dados coletados foram submetidos à ANOVA 2 fatores, seguido pelo pós-teste de Tukey e pelo teste de correlação de Spearman (α=0,05). Não houve concordância entre o try in e respectivo cimento, os valores de L* e b* aumentaram, tornando mais luminosa/opaca e amarelada. Todos grupos apresentaram valores superiores de ΔE=3,3, exceto o grupo do cimento cor A3 (cerâmica espessura de 1,0 mm) e as espessuras cerâmicas de 0,3 e 0,5 mm não influenciaram o GC, onde apresentaram valores sem diferença significativa (p>0,05) comparada ao grupo controle. Assim, o GC foi influenciado pela cor do cimento, onde o mais saturado apresentou maior taxa de conversão, ao passo que o valor de GC diminuiu quando a espessura do disco cerâmico interposto aumentou. Não houve relação entre o GC e ΔE.
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AVALIAÇÃO DE PROPRIEDADES DE UNIÃO DE ADESIVOS UNIVERSAIS AO CANAL RADICULAR PREPARADO COM DIFERENTES INSTRUMENTOS ROTATÓRIOS / Evaluation of bonding properties of universal adhesives to root canal prepared with different rotary instruments

Bakaus, Thaís Emanuelle 16 February 2016 (has links)
Made available in DSpace on 2017-07-24T19:22:01Z (GMT). No. of bitstreams: 1 Thais Bakaus.pdf: 1611331 bytes, checksum: 4d80c0ed64cbca5d883bbdad39b16c0d (MD5) Previous issue date: 2016-02-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this study was to evaluate the influence of a rotating device used to prepare the root canal in the adhesion of glass fiber posts and evaluate different bonding strategies using universal adhesive systems. One hundred human premolars were used, which had their crowns removed and their roots endodontically treated. Initially, the roots were divided into four groups, according to a combination of the factors: a rotating device used to prepare the root canal - carbide bur (CB) and diamond bur (DB) and cementation system (universal adhesive system associated with its respective resin cement - Single Bond Universal / RelyX ARC (SB) and Prime&Bond elect / Enforce (PB). They were then divided into subgroups according to the bonding strategy: Self-etch (SE) or Etch-and-rise (E&R). Eight teeth per group were evaluated in bond strength (BS) by the push-out test and 4 in nanoleakage teeth (NL) by scanning electron microscopy (SEM), and the roots for these tests were transversely sectioned in 6 slices. The data of BS and NI for each cementation system were subjected to 2-way ANOVA and Tukey (α = 0.05). For BS, only the major factors were significant (p <0.05), and for both cementation systems, the highest BS values were observed for the preparation with DB compared to the CB and SE adhesion strategy compared with E&R. Likewise, the interaction was not significant for NL (p> 0.05). For the cementation system PB, the lowest values were observed for groups using DB compared to the CB and SE adhesion strategy compared to E&R. For the SB cementation system, only the rotating device main factor was significant (p = 0.01), whereas the DB resulted in lower average nanoleakage compared to the CB. It can be concluded that to improve the adhesion of glass fiber posts to root canal, diamond bur should be used to prepare the root canal; and, in general, universal adhesive systems must be used in self-etch mode to obtain satisfactory results on intracanal adhesion. / Avaliou-se a influência do instrumento rotatório utilizado para preparo do conduto radicular na adesão de pinos de fibra de vidro e diferentes estratégias de adesão utilizando sistemas adesivos universais. Foram utilizados 100 pré-molares inferiores humanos, os quais tiveram suas coroas removidas e suas raízes tratadas endodonticamente. Inicialmente, as raízes foram divididas em quatro grupos, de acordo com a combinação dos seguintes fatores: instrumento rotatório utilizado para preparo do conduto radicular - broca carbide (BC) e ponta diamantada (PD) e sistema de cimentação (sistema adesivo universal associado com seu respectivo cimento resinoso) - Single Bond Universal/RelyX ARC (SB) e Prime&Bond elect/Enforce (PB). Foram divididos então em subgrupos de acordo com a estratégia de adesão: Self-etch (SE) ou Etch-and-rinse (E&R). Oito dentes por grupo foram avaliados em resistência de união (RU) pelo teste de push-out e 4 dentes em nanoinfiltração (NI) por microscopia eletrônica de varredura (MEV), sendo que para esses testes as raízes foram seccionadas transversalmente em 6 fatias. Os dados de RU e NI para cada sistema de cimentação foram submetidos à ANOVA 2 fatores e Tukey (α=0,05). Para RU, apenas os fatores principais foram significativos (p < 0,05), sendo que para ambos os sistemas de cimentação maiores valores de RU foram observados para o preparo radicular com PD em comparação com a BC e para a estratégia de adesão SE comparada a E&R. Da mesma maneira, a interação não foi significativa para NI (p > 0,05). Para o sistema de cimentação PB menores valores foram observados para os grupos que utilizaram PD em comparação com a BC e para a estratégia de adesão SE em comparação com a E&R. Para o sistema de cimentação SB, apenas o fator principal instrumento rotatório foi significante (p = 0,01), sendo que a PD resultou em menores médias de nanoinfiltração em comparação com a BC. Pode-se concluir que para melhorar a adesão de pinos de fibra de vidro ao canal radicular pontas diamantadas devem ser utilizadas para o preparo do conduto radicular; e, de maneira geral, os sistemas adesivos universais devem ser utilizados na maneira self-etch para obterem resultados satisfatórios de adesão intracanal.

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