Colour compatibility between teeth and dental shade guides in Quinquagenarians and Septuagenarians

Abstract

The aim of this investigation was to determine colour compatibility between dental shade guides, namely, VITA Classical (VC) and VITA 3D-Master (3D), and human teeth in quinquagenarians and septuagenarians. Tooth colour, described in terms of L*a*b* values of the middle third of facial tooth surface of 1391 teeth, was measured using VITA Easyshade in 195 subjects (48% female). These were compared with the colours (L*a*b* values) of the shade tabs of VC and 3D. The mean coverage error and the percentage of tooth colours being within a given colour difference (DeltaE(ab)) from the tabs of VC and 3D were calculated. For comparison, hypothetical, optimized, population-specific shade guides were additionally calculated based on discrete optimization techniques for optimizing coverage. Mean coverage error was DeltaE(ab) = 3.51 for VC and DeltaE(ab) = 2.96 for 3D. Coverage of tooth colours by the tabs of VC and 3D within DeltaE(ab) = 2 was 23% and 24%, respectively, (DeltaE(ab) </= 2 as clinically acceptable match). The hypothetical guides performed better and would only need seven to eight tabs to reach the same results as VC and 3D. Both guides had a mean coverage error that was too high and coverage that was too low according to an acceptable colour difference of tooth colour for these subjects. The optimized hypothetical, population-specific guides performed better indicating the possibility for improvement in colour compatibility of the guides with tooth colour in future shade guide development, allowing acceptable shade matching for most of the patients in clinical routine.

Determination of VITA Classical shades with the 3D-Master shade guide

“…It was, furthermore, confirmed that, in comparison with the VC, the 3D was extended toward yellow-red hues and more saturation [6]. In agreement with this finding, several studies of different population groups found that coverage of human tooth colors is better with the 3D than with the VC [7,8], although coverage by the 3D is not satisfactory for a small percentage of human tooth colors [6,9,10]. It has also been confirmed that the tabs of 3D are more ordered and more uniformly spaced than the tabs in traditional shade guides, although a genuinely uniform interval, on the basis of the color axes, between adjacent tabs could not be achieved [11].…”

Correlation of natural tooth colour with aging in the Spanish population

“…used the Easyshade (Vita‐Zahnfabrik) spectrophotometer and a minimum age of 18 years for participants. Cocking et al . and Eiffler et al .…”

“…This difference might be because the age of 58% of the sample was 21–30 years. Cocking et al . published a minimum L* value of 52.0 units and a maximum L* value of 90.0 units, whereas Zhu et al .…”

“…In the present study, the minimum value of a* was −3.0 and the maximum was 16.1. Cocking et al . described minimum and maximum values of a* units of −4.1 and 13.3, respectively.…”

Dental color matching instruments and systems. Review of clinical and research aspects

“…This discrepancy has been quantified by calculation of coverage error, the mean value of the minimal color differences amongst each tab in the shade guide and the database of human teeth. 17,[73][74][75][76] Although teeth exhibit color transitions in all directions, the correlation between colors of different regions on the labial tooth surface has been recorded. This study, performed using digital camera, suggested that color of a missing part of a tooth can be determined using the color of existing areas.…”