Biomodificação do colágeno dentinário por Cross-Linkers: efeito na rigidez do colágeno e na longevidade da união resina-dentina produzida pela técnica Dry-Bonding

• Autor(a) principal: Bianchi, Luciana [UNESP]
• Data de Publicação: 2015
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/145502; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/13-10-2016/000871154.pdf
• topic: Dentina; Colágeno; Resistência à tração; Dentin collagen

The aims of this study were to investigate the effect of the application of cross-linkers on (1) the stiffness of dentin collagen and (2) the resin-dentin bond degradation produced by the dry-bonding technique. To respond the first objective, forty 0.3 mm-thick dentin disks were obtained from sound premolars. After complete demineralization in 10% phosphoric acid, the discs were randomly divided into 4 groups according to the treatment (n=8): deionized water (control), 0.5 mol/L carbodiimide (EDC), 5% proanthocyanidin (PA) and 5% or 25% glutaraldehyde (GA). The discs were immersed in the solutions for 60s. Collagen stiffness was assessed indirectly based on the shrinkage after dehydration, measured in a linear variable differential transformer (LVDT). For second objective, flat dentin surfaces were produced in 64 sound pre-molars. The dentin was etched with phosphoric acid 37% for 15s, followed by treatment with the same solution described previously (n=16), except for the 25%GA. After the 60s treatment, the dentin was kept moist in half of the teeth (n=8) and dehydrated by air jets in the remaining teeth (n=8). Prime & Bond 2.1 adhesive was applied in all teeth followed by the built up of a composite block. Specimens of 0.81mm² adhesive area were obtained for the microtensile bond strength test, performed after 24h or 6 months of aging in saliva-like solution. After the mechanical test, the failure type was analyzed. Eight specimens by group were prepared for nanoleakage analysis. For both experiments, data were submitted to ANOVA and Tukey tests (p<0.05). In the absence of treatment with cross-linkers (control group), the percentage of shrinkage of the dentin matrix was 60%. Only EDC (23.9%) and glutaraldehyde 25% applied for 10 min (21.7%) were able to significantly reduce dentin shrinkage after dehydration. The highest bond strength values were found for EDC and 10% GA...(Complete abstract eletronic access below)