The purpose of this study was to compare the colorimetric values measured with the different lighting system sensors.
Colors of the central portion of the labial surface of the 16 upper central incisors of 8 adults aged from 23 years and 1 month to 34 years 9 months (average: 26 years 3 months) and 3 M Co. Silux Plus composite resin disks (shades: U, Y, DY, L, UO, YO) 1 mm in thickness were measured with the Murakami Color Research Laboratory Fast Spectro Photometer CMS-35 FS. The FSTL (trial production for semitranslucent objects) and the FS-3 (standard type) flexible sensors were used. The lighting system for the FS-TL is circumferencial illumination/diffuse transmission receiving and the lighting system for the FS-3 is the 45/0° configuration. The CIE L*a*b*color system was used for the determination of the color difference. The data was subjected to the Student t test (p<0.05).
1) Tooth Colors: The L* values of 14 teeth out of 16 teeth, the a* values of 14 teeth out of 16 teeth, and the b*, YI and C*ab values of all of the teeth measured with the FS-TL were significantly higher than those with the FS-3. The hab values of all of the teeth measured with the FS-TL were significantly lower than those with the FS-3.
2) Resin Colors: For L, UO and YO shades backed by a white plate and for all of the shades backed by a black plate, the L* values measured with the FS-TL were significantly lower than those with the FS-3. Both for resin specimens backed by a white plate or backed by a black plate, the a*, b*, YI and C*ab values of all of the shades measured with the FS-TL were significantly higher than those with the FS-3. Both for resin specimens backed by a white plate or backed by a black plate, the hab values of all of the shades measured with the FS-TL were significantly lower than those with the FS 3. The opacity % of all of the shades measured with the FS-TL were lower than those with the F-S-3.
3) Color Difference: The ΔE*ab between the values measured with the FS-TL and the FS-3 ranged from 1.05 to 16.96 for tooth colors and ranged from 28.97 (L) to 38.08 (Y) for resin colors backed by a white plate, and ranged from 23.71 (L) to 33.97 (U) for resin colors backed by a black plate.
4) Spectral Reflectance: In the comparison of the color measurement between the FS-TL and FS-3, both for tooth colors and resin colors, the spectral reflectances measured with the FS-TL showed higher reflectance in the high wave lengths (yellowish red to red color) but lower reflectance in the low wave lengths (purple blue to blue color).