Threshold value for the perception of color changes of human gingiva.

The aim of this study was to assess the threshold value for the perception of color changes of human gingiva. Standardized presentations of five cases in the esthetic zone were made with the gingiva and teeth separated. The color parameters L, a, and b (CIELab) of the gingival layers were adjusted to induce darker and lighter colors. In the presentations, the right side (maxillary right anterior) was unchanged, while the left side (maxillary left anterior) of the pictures was modified. Ten dentists, 10 dental technicians, and 10 lay people evaluated the color difference of the pictures. The mean ΔE threshold values ranged between 1.6 ± 1.1 (dental technicians) and 3.4 ± 1.9 (lay people). The overall ΔE amounted to 3.1 ± 1.5.