Purpose: To measure the validity and reliability of two gingival shade guides to represent in vivo gingival color using a Caucasian population sample.
Materials and methods: 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 and on the IPS d.SIGN physical gingival shade guides were collected to compare with the color coordinates taken in vivo. The coverage errors of the two shade guides evaluated were calculated using CIELab, and CIEDE 2000 formula and each area of the gingiva was compared with the 50:50% acceptability threshold for ΔE* = 4.6 and ΔE00* = 4.1. The spectroshade spectrophotometer was used.
Results: The IPS d.SIGN guide has similar coverage errors in all three areas and, in all cases, surpasses the 50:50% acceptability threshold. In contrast, the HeraCeram Gingiva guide has a lower coverage error in the free gingival margin than in the other two areas, and the coverage error remains below the 50:50% acceptability threshold only for δE00*. The HeraCeram gingiva shade guide has overall coverage errors (ΔE* = 7.9 and ΔE00* = 5.6) significantly lower than the coverage errors obtained for the IPS d.SIGN gingival shade guide (ΔE* = 9.2 and ΔE00* = 6.8).
Conclusion: Statistically significant differences were found in the coverage errors of both guides, both at the level of the three reference areas and at the global level. For both guides and in both sexes, the global coverage errors calculated with the CIELab and CIEDE2000 formulas were below the literature data on 50:50 acceptability thresholds.