EFFECT OF ONE–STEP POLISHING SYSTEM ON THE COLOR STABILITY OF NANOCOMPOSITES
Available online 23 October 2012
Abstract
Objectives
This study was to compare the effect of three different one-step
polishing systems on the color stability of three different types of
nanocomposites after immersion in coffee for one day and seven days and
determine which nanocomposite material has the best color stability
following polishing with each of the one-step polishing system.
Methods
The
nanocomposites tested were Tetric EvoCeram, Grandio and Herculite
Précis. A total of 120 discs (40/nanocomposite, 8 mm x 2 mm) were
fabricated. Ten specimens for each nanocomposite cured under Mylar
strips served as the control. The other specimens were polished with
OptraPol, OneGloss and Occlubrush immersed in coffee (Nescafé) up to
seven days. Color measurements were made with a spectrophotometer at
baseline and after one and seven days. Two way repeated measure ANOVA,
Two way ANOVA and Bonferroni tests were used for statistical analyses
(P < 0.05).
Results
The
immersion time was a significant factor in the discoloration of the
nanocomposites. The effect of three one-step polishing systems on the
color stability was also significant. The color change values of the
materials cured against Mylar strips were the greatest. The lowest mean
color change values were from the Occlubrush polished groups. The effect
of the three different types of nanocomposite on the color change was
significant. The highest color change values were with Tetric EvoCeram
groups. The lowest color change values were with Herculite Précis
groups.
Conclusion
The
color change of nanocomposite resins is affected by the type of
composite, polishing procedure and the period of immersion in the
staining agent.
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