OBJECTIVETo study the color changes on brightness and hue in dental ceramic prothesis materials.

METHODSThe different color mark of VINTAGE series was sintered on 15 pieces Ni-Cr alloy denture materials. The sample group and control group was given the sintering of color blending with equivalent volume. The order of color mark was of A1 and A2, A2 and A3, A3 and A4, B1 and B2, B2 and B3, B3 and B4 in sample group, and A1, A2, A3, A3.5, A4, B1, B2, B3 and B4 orderly in control group. The chromatic analysis on samples of VITA had been taken through applying PR 650 spectrum detector and adopted the statistic software of Photo Research and SPSS 12.0 for analysis.

RESULTSThe statistical difference (P<0.05) of L*a*b* value was found in the different color mark of the same color serials. A non-linearity relation had been found in the chromatic parameters a*b*. It means the change of color was visible.

CONCLUSIONSet A has a bigger grading change of brightness than Set B. The change of red-green is obviously in Set A, as well as yellow-blue in Set B.