Purpose: To measure the validity and reliability of two gingival shade guides used to represent in vivo gingival color in a Caucasian population sample.
Materials and Methods: The CIELAB color space was used to study three gingival reference areas (the free gingival margin, the keratinized gingival body, and the upper part of the keratinized gingiva) in a sample of 259 Caucasian individuals. The color coordinates on the HeraCeram Gingiva and on the IPS d.SIGN physical gingival shade guides were collected to compare with the color coordinates taken in vivo. The coverage errors (CEs) of the two shade guides were calculated using the CIELAB and CIEDE2000 formulas, and each area of the gingiva was compared with the 50:50% acceptability thresholds of ΔE* = 4.6 and ΔE00* = 4.1, respectively. The SpectroShade spectrophotometer was used.
Results: IPS d.SIGN showed similar CEs in all three areas and, in all cases, surpassed the 50:50% acceptability threshold. In contrast, HeraCeram Gingiva had a lower CE in the free gingival margin than in the other two areas, and the CE remained below the 50:50% acceptability threshold only for ΔE00*. The HeraCeram Gingiva shade guide had overall CEs (ΔE* = 7.9 and ΔE00* = 5.6) that were significantly lower than obtained for the IPS d.SIGN guide (ΔE* = 9.2 and ΔE00* = 6.8).
Conclusion: Statistically significant differences were found in the CEs of both guides, both at the level of the three reference areas and at the global level. For both guides and in both genders, the global CEs calculated with the CIELAB and CIEDE2000 formulas were below the literature data on 50:50% acceptability thresholds.
