Using Takagi-Sugeno-Kang approximation fuzzy logic for evaluating the performance of color difference formulas in dentistry

The present work carries out a novel study on the determination of color acceptability thresholds using a Takagi-Sugeno-Kang (TSK) fuzzy approximation, performing an evaluation of the CIEDE2000(K_L:K_C:K_H) color difference formula in dentistry. A total of 55 sample pairs were evaluated by a panel of 28 observers. The responses for each pair were processed, and data was fitted using a TSK Fuzzy Approximation, which in recent literature has proven to be a reliable and recommendable methodology for approximating color data in dentistry. 50:50% acceptability thresholds were calculated for both CIEDE2000(1:1:1) and CIEDE2000(2:1:1) formulas and the performance of these formulas was evaluated using the PF/3 and STRESS parameters. We obtained better values for all performance parameters for CIEDE2000(2:1:1), indicating the better agreement between this formula and the visual results. Our results suggest considering reviewing the parametric factors, so that the CIEDE2000 color difference formula can be properly used for further applications in dentistry.