CIEDE2000 lightness, chroma and hue human gingiva thresholds

Objective: : To determine the visual 50:50% perceptibility and acceptability CIEDE2000 lightness, chroma and hue human gingiva thresholds. Methods: : 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 (|delta L'/delta E-00| >= 0.98); chroma subset (|delta;C' /delta E-00| >= 0.98) and hue subset (|delta H'/delta E-00| >= 0.96) using & UDelta;E00 < 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). Results: : The 50:50% PT were delta L' = 0.74 (95% confidence interval (CI) 0.39-1.09); delta C' = 1.10 (95% CI 0.57-1.46); delta H' = 2.40 (95% CI 1.66-> 3.85). The 50:50% AT were delta L' = 2.57 (95% CI 2.00-3.06); delta C' = 2.70 (95% CI 2.19-3.38). AT delta H' 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. Conclusions: : 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 (delta H') than in chroma (delta C') and in lightness (delta L') in the gingiva color space. Clinical significance: : 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.

Automated summary

This study aimed to determine the thresholds for the perceptibility and acceptability of lightness, chroma, and hue of human gingiva. The results showed that observers were less sensitive to changes in hue (delta H'), but more sensitive to changes in chroma (delta C') and lightness (delta L') in the gingiva color space.