One-way analysis of variance (ANOVA) with
Tukey test was used to determine the significant differences
in hardnesses of the polished or celluloid
strip–finished composite surface for the time intervals
15 minutes, 6 hours, and 6 days after light curing.
From a pilot study, it had been confirmed that there
was no difference in the hardness between the upper
and lower surfaces of 1.5 mm thick composite, which
had been light cured in the same mold for our study.
This is consistent with a previous study.10