The effect of hydrofluoric acid and resin cement formulation on the bond strength to lithium disilicate ceramic

Author(s)

Sundfeld, Daniel ; Muniz Palialol, Alan Rodrigo ; Fugolin, Ana Paula Piovesan ; Bovi Ambrosano, Glaucia Maria ; Correr-Sobrinho, Lourenco ; Marcondes Martins, Luis Roberto ; Pfeifer, Carmem Silvia

• Document type: Journal article
• Source: BRAZILIAN ORAL RESEARCH; v. 32, p. 10-pg., 2018-01-01.

Abstract

To investigate how the hydrofluoric acid (HF) concentrations applied to a lithium disilicate glass-ceramic (EMX) affects the surface morphology and microtensile bond strength (mu TBS) of ceramics to dentin, using light-cured resin cements with or without UDMA. Sixty-three EMX square ceramic blocks were etched for 20 seconds using different HF concentrations (1%, 5% and 10%) and luted to dentin using two types of resin cement combinations: BisGMA/TEGDMA and BisGMA/TEGDMA/UDMA (n = 10). Each bonded EMX-dentin block was sectioned to obtain 1 mm(2) sticks for mu TBS evaluation. Half of the sticks were tested after 24 hours and the other half was assessed after 6 months of water storage. Data were statistically assessed using split-plot three-way ANOVA and multiple comparisons were performed using the Tukey's post hoc test (alpha = 0.05). One EMX sample from each HF concentration was analyzed using field-emission scanning electron microscope (FE-SEM) to characterize the etching pattern. According to the FE-SEM images, increasing the concentration of HF from 1 to 5 and then to 10% led to increased removal of glassy matrix and greater exposure of lithium disilicate crystals. The 10% HF concentration yielded higher mu TBS when compared to 1% for BisGMA/TEGDMA formulation (p < 0.05); whereas HF 1% and 5% showed similar mu TBS values when compared to 10% HF for BisGMA/TEGDMA/UDMA resin matrix (p > 0.05) at both storage times. Water aging decreased the mu TBS values (p < 0.05), except when 10% HF was associated with BisGMA/ TEGDMA resin cement. Resin cement formulation and hydrofluoric acid concentrations can interfere with the immediate and long-term glass-ceramic bond strength to dentin. (AU)

• FAPESP's process: 14/23320-3 - Influence of hydrofluoric acid concentration and previous thermal treatment on bond strength of lithium disilicate glass ceramic to a dual-cure resin cement modified by thio-urethane
• Grantee: Daniel Sundfeld Neto
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 13/26573-7 - Effects of hydrofluoric acid concentration and thermal treatment on bond strenght to dental ceramic
• Grantee: Daniel Sundfeld Neto
• Support Opportunities: Scholarships in Brazil - Doctorate