Analyse the color of tetracycline teeth

OBJECTIVES: Analyse the color's difference between the tetracycline teeth and normal teeth . METHODS: 1.100 cases with each group of tetracycline teeth and normal teeth, the NO.11,13 teeth of everyone were scaled by Shade Eye-NCC colorimeter by one experimenter. The results of "L*/a*/b*" and "Shade/Value/Hue" were recorded and compared with a T test statistical method(SAS 6.12 for windows). &Delta E was also calculated [&DeltaE=(&DeltaL*2+&Deltaa*2+&Deltab*2)1/2] and compared. 2.Calculate the chromatism &Delta E between the NO.11 and NO.13 of the tetracycline-tooth data .The &DeltaE was compared with the the normal teeth . RESULTS:1.Significant difference of L*,a* was found between the "tetracycline-tooth "and "normal-teeth" (P<0.01); About b* value, there are significant difference with NO.11 tooth and no significant difference with NO.13 tooth(P>0.05).According to the Mean of L*,a*,b*, the color of "tetracycline-tooth" group was darker,redder and yellower.2.Significant difference of Shade,Value,Hue was found between the "tetracycline-tooth" and "normal-teeth" (P<0.01); The mean value of Shade,Hue of "tetracycline-tooth" is higher than that of "normal-teeth", but Value is lower. The color of tetracycline-tooth was darker,denser, the hue is close to R3.3.Between the NO.11 and13, the &DeltaE in the tetracycline-tooth is lower than that of normal teeth, we can find the color difference more easier in the normal teeth by our naked eye.CONCLUSIONS: The tetracycline-tooth is darker/redder and yellower than the normal teeth. The chroma of the tetracycline-tooth is increased and the hue tend to red.