Evaluation of various polishing systems and the phase transformation of monolithic zirconia
Available online 7 April 2016
Abstract
Statement of problem
Although
a well-polished monolithic zirconia surface is essential, insufficient
comparative studies on the constituents and efficacy of polishing
systems have been conducted.
Purpose
The
purpose of this in vitro study was to analyze the abrasive constituents
and compare the polishing effectiveness of 6 zirconia polishing
systems, including their potential influence on the phase transformation
of monolithic zirconia.
Material and methods
The
compositions of 6 zirconia polishing systems were analyzed using energy
dispersive spectroscopy (EDS). Sintered and high-speed ground
monolithic zirconia specimens were used as control groups (n=14
specimens per group). Test groups (n=168) were pretreated identically to
the control group and arbitrarily divided into 12 groups to examine 6
polishing systems for 2 polishing periods (60 or 120 seconds). The
surfaces were characterized by a surface profiler and various analytic
techniques, including x-ray diffraction (XRD) analysis. The data were
analyzed using 2-way ANOVA and multiple comparisons and the Bonferroni
method (α=.05).
Results
The
abrasives were primarily composed of C, O, and Si. Diamond was
identified as the main abrasive and SiC as the supplementary abrasive in
the polishing systems. No significant differences were observed for the
60- or 120-second polishing times (P>.05). Four products had significantly lower surface roughness values than the other 2 (P<.001).
The occlusal-adjustment-simulating pretreatment and polishing processes
did not cause phase transformations in the zirconia specimens.
Conclusions
The
monolithic zirconia polishing systems contained diamond and SiC
abrasives. All zirconia polishing systems showed clinically acceptable
results, and 4 systems exhibited lower surface roughness. Phase
transformation did not occur during polishing procedure.
Comments