Influência do sistema de cimentação adesiva e da fonte de luz fotoativadora na resistência à extrusão de pinos de fibra de vidro
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Data
2009-03-03
Autores
Lima, Luiz Rafael Calixto [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A retenção de pinos pré-fabricados de fibra de vidro, utilizados na restauração de dentes com tratamento endodôntico, é baseada na sua união às superfícies das paredes do canal radicular, por meio dos agentes de fixação resinosos. O tipo de pino utilizado, assim como a fonte de luz fotoativadora do cimento, também pode influenciar nessa retenção, principalmente nas regiões mais críticas do canal, como o terço apical, onde há uma grande dificuldade de acesso dessa luz ativadora. Assim, o propósito deste trabalho foi avaliar comparativamente a influência de diferentes sistemas de cimentação (químico convencional; dual convencional, químico com adesivo auto-condicionante, dual com adesivo auto-condicionante e cimento dual auto-adesivo), na resistência à extrusão (push-out) de pinos de fibra de vidro, nos diferentes terços do canal (cervical, médio, aplical). Foi avaliada também a influência do tipo de fonte de luz fotoativadora do cimento: luz halógena (Optilux 501) e LED (Ultraled). O tipo de falha foi avaliado através de microscopia. Foram utilizadas 240 unidades experimentais, em forma de discos, com aproximadamente 1 mm de espessura, retirados de 80 raízes bovinas, restauradas com retentores intraradiculares. Foi utilizada uma máquina de ensaios universais, MTS 810 Material Test System, à velocidade de 0,5 mm/min-1, com célula de carga de 50 Kg, para avaliação da resistência push-out nos diferentes terços de cada corpo-de-prova. Os valores de resistência em kgf, foram convertidos para MPa e analisados por meio de Análise de Variância e teste de Tukey, com nível de significância de 5%. Os resultados mostraram baixos valores de retenção para os grupos com os cimentos autoadesivos,independente da fonte de luz utilizada. Os cimentos de condicionamento ácido total e os de adesivos auto-condicionantes parecem ser opções viáveis no processo...
The retention of prefabricated glass fiber posts, used for the restoration of endodontically-treated teeth, is based on adhesive systems and resin luting cements. The type of posts used, as well as the type of activation of the cement can also influence this retention, mainly in more critical areas of the radicular dentin, such as the apical root segments, where there is a great difficult access of the light curing units. Thus, the purpose of this study was to evaluate the influence of different resin cements (Chemical-cure total-etch; dual-cure total-etch; chemicalcure and self-etch bonding system, dual-cured and self-etch bonding system; and dual-cure self-adhesive cement) on the bond strength (push-out) of glass fiber posts on the different thirds of the root (cervical, middle and apical). The influence of the light curing unit was evaluated by halogen LCU (Optilux 501) and by LED LCU (LEC II 470) use. The failure mode was evaluated by stereoscopic microscope. Disks of the samples (n=240) were used, with approximately 1 mm of thickness of 80 bovine roots restored with glass fiber posts. A universal testing machine (MTS 810 Material Test System) was used with a 1 mm diameter steel rod at cross-head speed of 0,5 mm/min until post extrusion, with load cell of 50 kg, for evaluation of the push-out strength in different thirds of each sample. The pushout strength values in kgf were converted to MPa and analyzed through Analysis of Variance and Tukey’s test, with significant level of 5%. The results of the present study showed that the self-adhesive cements group resulted in low retention values, in every light source utilized. The total-etch cements and the self-etch bonding systems seem to be a viable alternative in the glass fiber posts cementation process, with either halogen light or LEDs.
The retention of prefabricated glass fiber posts, used for the restoration of endodontically-treated teeth, is based on adhesive systems and resin luting cements. The type of posts used, as well as the type of activation of the cement can also influence this retention, mainly in more critical areas of the radicular dentin, such as the apical root segments, where there is a great difficult access of the light curing units. Thus, the purpose of this study was to evaluate the influence of different resin cements (Chemical-cure total-etch; dual-cure total-etch; chemicalcure and self-etch bonding system, dual-cured and self-etch bonding system; and dual-cure self-adhesive cement) on the bond strength (push-out) of glass fiber posts on the different thirds of the root (cervical, middle and apical). The influence of the light curing unit was evaluated by halogen LCU (Optilux 501) and by LED LCU (LEC II 470) use. The failure mode was evaluated by stereoscopic microscope. Disks of the samples (n=240) were used, with approximately 1 mm of thickness of 80 bovine roots restored with glass fiber posts. A universal testing machine (MTS 810 Material Test System) was used with a 1 mm diameter steel rod at cross-head speed of 0,5 mm/min until post extrusion, with load cell of 50 kg, for evaluation of the push-out strength in different thirds of each sample. The pushout strength values in kgf were converted to MPa and analyzed through Analysis of Variance and Tukey’s test, with significant level of 5%. The results of the present study showed that the self-adhesive cements group resulted in low retention values, in every light source utilized. The total-etch cements and the self-etch bonding systems seem to be a viable alternative in the glass fiber posts cementation process, with either halogen light or LEDs.
Descrição
Palavras-chave
Pinos dentários, Cimentos de resina, Técnica para retentor intra-radicular, Dental pins, Post and core technique, Resin Cements
Como citar
LIMA, Luiz Rafael Calixto. Influência do sistema de cimentação adesiva e da fonte de luz fotoativadora na resistência à extrusão de pinos de fibra de vidro. 2009. 95 f. Dissertação (mestrado) - Universidade Estadual paulista, Faculdade de Odontologia de Araraquara, 2009.