Silanization effect on microtensile bond strength of a self-adhesive luting material to a disilicatebased glass ceramic

Resumo

The rehabilitation of teeth by means of ceramic
indirect restorations has been widely performed. Previous studies
has shown the effectiveness of silane coupling agents on improving
the bond strength of the adhesion of resin cements to ceramics;
however, some studies question the use of silane. Objective: To
evaluate the effect of silane application on the microtensile bond
strength of an auto-adhesive luting material to a lithium disilicate
glass-ceramic. Material and methods: Two blocks (9x11x4mm) of
lithium disilicate glass-ceramic had one of their surfaces polished
(# 220, 360, 600 grit silicon-carbide abrasive papers) and cleaned
ultrasonically. The ceramic blocks were then divided into two groups
according to the surface treatment: G1 (control group): etched with
10% hydrofluoric acid for 20s and silane coated; G2: etched with
10% hydrofluoric acid for 20s. After building two blocks of composite
resin (Filtek Z350) with the same dimensions of the ceramic blocks,
the self-adhesive resin cement (SpeedCEM) was applied directly to the
ceramic surface and the resin block was seated on the cement. After
storage (24h, 37°C), the ceramic-cement-composite blocks were cut
with an Isomet low-speed diamond saw machine producing sticks,
which were loaded to failure at a crosshead speed of 0.5 mm/min.
The type of fracture was analyzed under an optical microscope. The
results were statistically analyzed using the Student t test. Results:
The mean microtensile and standard deviations in megaPascals were: G1 = 21.32 (± 4.36) and G2 = 16.55 (± 4.92). Statistical analysis
showed that the bond strength was not significantly affected by the
surface treatment with silane. Most of the fractures occurred within
the adhesion zone. Conclusion: The application of silane had no
significant effect on the bond strength between lithium disilicate
glass-ceramic and self-adhesive resin cement.