CIEDE2000 lightness, chroma and hue human gingiva thresholds

• Published in: Journal of dentistry 2022-09, Vol.124, p.104213-104213, Article 104213
• Main Authors: Pérez, María M., Carrillo-Perez, Francisco, Tejada-Casado, Maria, Ruiz-López, Javier, Benavides-Reyes, Cristina, Herrera, Luis Javier
• Format: Article
• Language: English
• Subjects: Acceptability; Chroma; CIEDE2000; Dentistry; Dentists; Evaluation; Gingiva; Hue; Human gingiva; Lightness; Observers; Psychophysics; Software; Statistical analysis; Thresholds; Visual thresholds
• ISSN: 0300-5712; 1879-176X
• DOI: 10.1016/j.jdent.2022.104213

•There are differences in sensitivities between ΔL′, ΔC′, ΔH′ for human gingiva.•Lightness and chroma gingiva mismatches are more difficult to be accepted than hue.•PT and AT should be used for natural gingiva and pink gingival materials evaluation.•PT and AT should be used for the development of new pink gingival shade guides. : To determine the visual 50:50% perceptibility and acceptability CIEDE2000 lightness, chroma and hue human gingiva thresholds. : A psychophysical experiment based on visual assessments of simulated images of human gingiva on a calibrated display was performed. A 20-obsever panel (dentists and laypersons; n=10) evaluated three subsets of simulated human gingiva: lightness subset (|ΔL′/ΔE00|≥ 0.98); chroma subset (|ΔC′/ΔE00|≥ 0.98) and hue subset (|ΔH′/ΔE00|≥ 0.96) using ΔE00< 5 units. A Takagi-Sugeno-Kang (TSK) Fuzzy Approximation model was used as fitting procedure, and 50:50% perceptibility threshold (PT) and acceptability threshold (AT) were calculated. Data was statistically analyzed using t-test (p ≤ 0.05). : The 50:50% PT were ΔL’ = 0.74 (95% confidence interval (CI) 0.39−1.09); ΔC’ = 1.10 (95% CI 0.57−1.46); ΔH’ = 2.40 (95% CI 1.66->3.85). The 50:50% AT were ΔL’ = 2.57 (95% CI 2.00−3.06); ΔC’ = 2.70 (95% CI 2.19−3.38). AT ΔH’ may be considered no computable. PT values were statistically significant among the three metric differences (p ≤ 0.05). No difference was found between observers for PT values. : Statistically differences in perceptual limit were found among hue, lightness and chroma for human gingiva. Thus, the observers seem to show lower sensitivity for changes in hue (ΔH′) than in chroma (ΔC′) and in lightness (ΔL′) in the gingiva color space. : PT and AT for lightness, chroma and hue specific for human gingiva should be used when evaluating natural gingiva, pink gingival shade guides or pink materials, since the thresholds of perception and acceptability for teeth are not suitable.