Influence of the LED curing source and selective enamel etching on dentin bond strength of self-etch adhesives in class I composite restorations
DOI: 10.1007/s10103-011-1030-y
Abstract
The
aim of this study was to evaluate the influence of the LED curing unit
and selective enamel etching on dentin microtensile
bond strength (μTBS) for self-etch adhesives in class I
composite restorations. On 96 human molars, box-shaped class I cavities
were made maintaining enamel margins. Self-etch adhesives
(Clearfil SE – CSE and Clearfil S3 – S3) were used to bond a
microhybrid composite. Before adhesive application, half of the teeth
were enamel acid-etched and
the other half was not. Adhesives and composites were cured
with the following light curing units (LCUs): one polywave (UltraLume
5 - UL) and two single-peak (FlashLite 1401 - FL and Radii
Cal - RD) LEDs. The specimens were then submitted to thermomechanical
aging and longitudinally sectioned to obtain bonded sticks
(0.9 mm2) to be tested in tension at 0.5 mm/min. The failure
mode was then recorded. The μTBS data were submitted to a three-way
ANOVA
and Tukey’s (α = 0.05). For S3, the selective enamel-etching
provided lower μTBS values (20.7 ± 2.7) compared to the non-etched
specimens (26.7 ± 2.2). UL yielded higher μTBS values
(24.1 ± 3.2) in comparison to the photoactivation approach with FL (18.8
±3.9) and RD (19.9 ±1.8) for CSE. The two-step CSE was not
influenced by the enamel etching (p ≥ 0.05). Enamel acid etching in class I composite restorations affects the dentin μTBS of the one-step self-etch adhesive
Clearfil S3, with no alterations for Clearfil SE bond strength. The polywave LED promoted better bond strength for the two-step adhesive
compared to the single-peak ones.
Comments