Bonding performance of universal adhesives in different etching modes.
Available online 6 May 2014
Abstract
Objectives
The
aim of this study was to compare the microtensile bond strength (μTBS)
and resin penetration into dentin of three universal adhesives (UAs)
applied in two different etching modes (i.e. self-etch or
etch-and-rinse). The effect of thermocycling on the μTBS was also
evaluated.
Methods
The
occlusal third of sound human molars was removed and the exposed
surfaces were treated with three UAs (Futurabond Universal, Scotchbond
Universal Adhesive and All-Bond Universal) in self-etch or
etch-and-rinse mode. Two one-step self-etch adhesives (Futurabond DC and
Futurabond M) were applied on additional teeth as reference. After
composite build up, the specimens were stored for 24 hours in distilled
water at 37° C or thermocycled for 5000 cycles. Composite/dentin beams
were prepared (1 mm2) and μTBS test was performed. Data was
analyzed using three-way ANOVA and Tukey's test (α=0.05). One additional
tooth was prepared for each group for evaluation of infiltration
ability into dentin by dyeing the adhesives with a fluorochrome
(Rhodamine B). After longitudinal sectioning, the generated interfaces
were examined under confocal light scanning microscopy.
Results
The
addition of an etching step did not significantly affect the μTBS of
none of the UAs, when compared to their self-etch application mode. All
pre-etched specimens showed considerably longer resin tags and thicker
hybrid layers. Thermocycling had no significant effect on the μTBS of
the UAs.
Conclusion
Application
of an etching step prior to UAs improves their dentin penetration, but
does not affect their bond strength to dentin after 24 h or after
thermocycling for 5000 cycles.
Clinical Significance:
Similar bond strength values were observed for the UAs regardless of
application mode, which makes them reliable for working under different
clinical conditions.
Comments