Journal of Medical Sciences1682-44741812-5727Asian Network for Scientific Information10.3923/jms.2008.77.80GhanbarzadehJ. SabooniM.R. TehraniN. Amiri 1200881The aim of this study was to evaluate the effect of repeated firings
on the color stability of Vita VMK95 and Ivoclar IPS classic metal ceramic
porcelain systems using a colorimetric. In this experimental in vitro
study, 24 disc-shaped specimens, 10 mm in diameter with a 0.3 mm base
metal alloy (Supercast) thickness were prepared and two types of porcelains,
a 0.2 mm opaque and a one millimeter dentine porcelain (Shade A3) thickness,
were applied on them. Samples were fired one, three and six times. Color
measurement was carried out after each firing using a colorimeter (Minolta,
CR-10) and data were expressed in Commission Internationale I`Eclairage
(CIE-LAB) system coordinates. In this study, the parametric paired t-test
was used to analyze the data. After six times of firing the l*, a* and
b* parameters were significantly different, before and after aging, for
Vita VMK95 (respectively p = 0.043, p = 0.002, p<0.001); however for
Ivoclar IPS classic, only a* parameter was significant difference before
and after aging (p<0.001). After repeated firing, color stability of
Ivoclar IPS classic was better than Vita VMK95 porcelain.]]>Baumarn, M.A. and E.B. Schiffered,1994104423429Cho, M.S., Y.K. Lee, B.S. Lim and Y.J. Lim,200695437443Craig, R.G., J.M. Powers and J.C. Wataha,20048th Edn.,Douglas, R.D. and M. Przybylska,199982143149O'Brien, W.J., K.S. Kay, K. Benke and C.L. Groh,19917170173Powers, J.M. and R.L. Sakaguchi,200612 Edn.,Rosenstiel, S.F. and W.M. Johnston,198860297303Rosenstiel, S.F., M.F. land and J. Fujimoto,20064th Edn.,pp: 209-258pp: 209-258Uludag, B., A. Usumez, V. Sahin, K. Eser and E. Ercoban,2007in vitro study.]]>972531Wu, X.M. and Z. Zhou,200426423425