Correlation of Two Shade Guides for Evaluating tooth Bleaching Efficacy

Objective: Vitapan Classical Shade Guide (VC, Vita Zahnfabrik, Germany) has been used most commonly for evaluating tooth bleaching efficacy but it lacks linearity.� The newly developed Vita Bleachedguide 3D-Master (VBG, Vita Zahnfabrik, Germany) is linear with equal color intervals.� The purpose of the study was to investigate consistency and correlation of the VC and VBG for shade judgment among experienced dental clinicians.� Methods: Three dentists each with >10-year clinical experience performed visual shade-matching of the VC to VBG with a black background under color-corrected dental office lighting.� Each investigator conducted shade-matching procedures independently for three times, with an interval of at least one week between two evaluations, using the same shade guides, lighting conditions and environmental surroundings. �The data were analyzed for intra- and inter-examiner correlations as well as the correlation between the VC and VBG using the Pearson Correlation method. �Results: A significant correlation was detected within and between three investigators for the same shade guide (r >0.917). �There were variations in shade matching between the VC and VBG as well as among the three investigators.� While the VC correlated significantly with the VBG for all investigators and their averages (r >0.983), four VBG shades (0M1, 0.5M1, 1M1 and 5M3) did not match any of the 16 VC shades.� In addition, none the remaining 11 VBG shades matched only one VC shades, with some VBG shades matching multiple VC shades.� Variations also existed among three investigators in shade-matching between the VC and VBG shade guides. �Conclusions: The visual shade judgment is highly consistent and correlated for either the VC or VBG within and among three dentists.� While there is a correlation between the VC and VBG, variations exist even among experienced clinicians.