Περίληψη:
Statement of problem. The color of dental porcelain depends on the type
of metal substrate. Little research has been done to document the
effects of different types of high-palladium alloys on the color of
dental porcelain.
Purpose. The purpose of this in vitro study was to evaluate the effects
of different high-palladium alloys on the resulting color of dentin
porcelain, as well as on that of opaque porcelain after simulated dentin
and glazing firing cycles.
Material and methods. Three Pd-Cu-Ga alloys, Spartan Plus (S), Liberty
(13), and Freedom Plus (F), and 5 Pd-Ga alloys, Legacy (L), IS 85 (1),
Protocol (P), Legacy XT (X), and Jelenko No. 1 (N), were examined. A
Pd-Ag alloy, Super Star (T), was included for comparison to the
high-palladium alloys, and the Au-Pd alloy, Olympia (0), served as the
control. Six cast discs (16 X I mm) were prepared from each of the
alloys. Shade B I opaque porcelain (Vita-Omega) was applied at a final
thickness of 0.1 mm. After 2 opaque porcelain firing cycles, the
surfaces were airborne-particle abraded, and the specimens were divided
into 2 groups. In the first group, 0.9 mm of B1 dentin porcelain was
applied. The other group of specimens with only opaque porcelain
underwent the same dentin porcelain and glazing firing cycles. Color
differences (DeltaE) were determined with a colorimeter between the
control and each experimental group, after the second opaque porcelain,
second dentin porcelain, and glazing firing cycles. One-way analysis of
variance and Dunnett’s multiple range test were performed on the DeltaE
data (alpha=.05).
Results. After the application of dentin porcelain, the 3 Pd-Cu-Ga
alloys showed significantly different (P<.05) Delta E values (S = 2.3
+/- 0.5, B = 1.4 +/- 0.3, and F = 1.3 +/- 0.7) than the control group.
After the glazing cycle of this group, the 3 Pd-Cu-Ga alloys and the
Pd-Ag alloy exhibited significantly different (P<.05) DeltaE values (S =
2.8 +/- 0.8, B = 2.2 +/- 0.3, F = 1.9 +/- 1.0, and T = 1.4 0.5) than the
control group. After the simulated dentin porcelain firing cycles, the
specimens with only opaque porcelain exhibited significantly different
(P<.05) Delta E values (S = 5.2 +/- 1.4, B = 5.4 +/- 0.6, and F = 3.9
+/- 0.2) than the control group. The color difference between the 3
Pd-Cu-Ga alloys with only opaque porcelain and the control group
increased more after the simulated glazing cycle (S = 6.6 +/- 1.5, B =
6.3 +/- 0.5, and F = 4.6 +/- 0.1). The observed color differences
between the Pd-Ga alloys and the control group were not statistically
significant at any point.
Conclusions. The Pd-Cu-Ga alloys with only opaque porcelain, after the
simulated dentin porcelain and glazing firing cycles, exhibited
clinically unacceptable color differences. The application of dentin
porcelain to the Pd-Cu-Ga alloys resulted in clinically acceptable color
differences. The application of dentin porcelain to the Pd-Ag alloy,
after the glazing firing cycle, resulted in clinically acceptable color
differences (approximately 2.8 to 3.7 Delta E CIELAB units). The Pd-Ag
alloy specimens with only opaque porcelain did not exhibit significant
color differences from the control group, whereas significant color
differences from the control group after the dentin porcelain and
glazing firing cycles were still clinically acceptable.
Συγγραφείς:
Stavridakis, MM
Papazoglou, E
Seghi, RR
Johnston, WM and
Brantley, WA
