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Effect of different high‐palladium metal‐ceramic alloys on the color of opaque porcelain
Author(s) -
Stavridakis Minos M.,
Papazoglou Efstratios,
Seghi Robert R.,
Johnston William M.,
Brantley William A.
Publication year - 2000
Publication title -
journal of prosthodontics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.902
H-Index - 60
eISSN - 1532-849X
pISSN - 1059-941X
DOI - 10.1111/j.1532-849x.2000.00071.x
Subject(s) - opacity , dental porcelain , alloy , colorimeter , palladium , materials science , metallurgy , amalgam (chemistry) , metal , ceramic , chemistry , physics , optics , catalysis , biochemistry , electrode
Purpose The purpose of this study was to assess the effect of different high‐palladium alloys on the resulting color of opaque porcelain. Three Pd‐Cu‐Ga alloys, Spartan Plus (S; Williams Dental Co/Division of Ivoclar North America, Amhest, NY), Liberty (B; J.F. Jelenko & Co, Armonk, NY), and Freedom Plus (F; J.F. Jelenko & Co); 4 Pd‐Ga alloys, Legacy (L; J.F. Jelenko & Co), IS 85 (I; Williams Dental Co), Protocol (P; Williams Dental Co), and Legacy XT (X; J.F. Jelenko & Co); and a Pd‐Ag alloy, Super Star (T; J.F. Jelenko & Co), were examined. The Au‐Pd alloy Olympia (O; J.F. Jelenko & Co) served as the control. Materials and Methods Three cast 16‐mm discs, 1‐mm thick, were prepared from each of the alloys. After metallurgically polishing and air‐abrading, the specimens were oxidized following the manufacturer's recommendations. Shade B1 opaque porcelain (Vita‐Omega; Vident, Baldwin Park, CA) was applied at a final thickness of 0.1 mm using a mold. After 2 opaque porcelain firing cycles, the surfaces were air‐abraded. The colors of the specimens were measured using a colorimeter and expressed in Commission International de l'Eclairage (CIE) L*a*b* coordinates. Color differences (ΔE) were determined between the control and each experimental group. Analysis of Variance and Tukey‐Kramer tests were performed on the ΔE data. Results The 3 Pd‐Cu‐Ga alloys showed significantly greater ( p < .01 ) ΔE values ( S = 2.8 ± 1.1, B = 3.0 ± 0.6 , and F = 2.1 ± 0.2 ) than the remaining 5 experimental groups ( L = 0.7 ± 0.5, I = 0.7 ± 0.4, P = 0.7 ± 0.2, X = 0.7 ± 0.4 , and T = 0.7 ± 0.5 ). The directions of the significant color changes were relatively equally distributed along the L*, a*, and b* axes, and all ΔL*, Δa*, and Δb* values were negative (lower value, more green and blue relative to control O). Conclusions This work suggests that a 0.1‐mm‐thick layer of opaque porcelain in the Pd‐Cu‐Ga alloys studied, did not reliably reproduce the color of porcelain.