Influences of light temperature and room wall colors on tooth shade matching

Aim: This in vitro study investigates how light temperature and room wall colors influence color differences in two commonly used tooth shade guide scales for color selection in dentistry. Methods: We examined the effects of three light temperatures (warm light at 3000K, neutral light at 4000K, cool light at 6500K), four room wall colors (white, blue, red, black), chromatic shade values (low, medium, high), and two shade-guide scales (Vita Classical and Biotone). Color differences were measured using an EasyShade spectrophotometer, with ΔE00 calculated via the CIEDE2000 method to assess perceptibility and acceptability thresholds. Results: The study revealed that high chromatic shade values on both scales showed a greenish shift in the a* coordinate, while medium and low values inclined towards redness. All b* values exhibited a tendency towards yellowness. For the Vita Classical scale, neutral light conditions did not significantly affect ΔE00 across any room wall colors (p > 0.05). However, for the Biotone scale, high chromatic values under specific light conditions significantly surpassed the clinical perceptibility threshold in white versus red room simulations (p < 0.05), indicating a notable impact on color perception. Conclusions: Our findings suggest that both light temperature and room wall color significantly affect tooth shade perception. Adjustments in environmental conditions can corroborate for more accurate color matching between natural tooth and dental restorations. Special attention must be given to extreme light temperatures and contrasting wall colors. These results support the importance of standardized environmental settings in dental practices to ensure reliable esthetic outcomes.