Influence of the Labial Surface Irregularity on Measuring Tooth Color

Objectives: This study was conducted to evaluate what effect of the surface irregularity on the labial surface of the teeth to the results of the color measured by color measuring instrument. Methods: 11 models of the teeth were made by injecting the A2 shade Luxatemp Automix Plus (DMG, Germany) into the impression acquired from 11 adults. And, standard samples were made with same material by Teflon mold (4 mm in thickness, 15 mm in diameter). CIE L*a*b* value was measured at the incisal area, central area, and gingival area of the central incisor, lateral incisor, canine and 1st premolar using Specbos 2100 (JETI, Germany) spectroradiometer. And color difference was calculated between color of labial surface and standard sample. Results: In each tooth, the color difference (¢E*) of each area decreased in the order of between the incisal and gingival area, between the incisal and central area, and between the central and gingival area (p<0.05). The color difference from the comparison of standard samples showed the most difference in the incisal area of all teeth, and the gingival area showed the least difference. The canine showed the least color difference from the comparison of standard sample compared to the other teeth, and the central incisor showed most color difference. Conclusion: Color measurement of teeth using color measuring devices can be influenced by type and measured area of teeth.