Influence of etching time and adhesive system on shear bond strength and compression resistance of the reinforced leucite ceramic

• Autor(a) principal: Libardi, Camila Cruz
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
• Texto Completo: http://www.teses.usp.br/teses/disponiveis/25/25148/tde-05092019-205033/
• topic: Ceramics; Compressive strength; Hydrofluoric acid; Shear bond strength

This in vitro study evaluated the bond and compression strength of cemented leucite reinforced glass ceramics in bovine tooth enamel, comparing three etching times with hydrofluoric acid 10% of the ceramic surface (20, 60 and 90 seconds) and two adhesive treatments (adhesive system + silane and universal adhesive system). For the bond strength test, 120 ceramic cylinders (2mm diameter x 2mm length; n=20) were etched and cemented (80m thick) in enamel with a dual resin cement, varying the adhesive treatment, obtaining the groups: UEXC20s, UEXC60s, UEXC90s, USBU20s, USBU60s, USBU90s. After 24 hours, the shear bond strength test was performed on a universal test machine (0.5mm/min, 50kgf). For the compression test, 30 ceramic plates (5x5mm with 1mm thick, n=5) were etched, received the same adhesive treatments and were cemented (80m) in enamel, obtaining the following groups: CEXC20s, CEXC60s, CEXC90s, CSBU20s, CSBU60s, CSBU90s. After 24 hours of cementation, the compression test (0.5mm/min, 500kgf) was performed. Statistical analysis was performed using two-way ANOVA and Tukey test (=.05). For the shear bond strength test significant differences were found among the adhesives (p<.05). For the etching times there were no differences (p=.059). However, there was a significant interaction between the adhesives and the etching times (p=.021). At 60 seconds, the Silane + ExciTE F DSC Adhesive presented the highest bond strength values (47.53±16.70Mpa). And at 20 seconds, the Universal adhesive presented the lowest bond strength values (27.72±10.76Mpa). For the compression test there were no significant differences between the adhesives (p=.571) and between the times (p=.154). The group that presented the highest values of compression force was the Universal adhesive at 60 seconds (1757.89±200.47N). The lowest values were also the Universal adhesive, but at 90 seconds (1213.30±546.34N). The study concluded that the silane associated with the ExciTE F DSC adhesive showed the highest bond strength values at the etching time of 60 seconds with 10% hydrofluoric acid, without compromising the compressive strength of the leucite reinforced ceramic.