Effects of Different Color Measurement Methods on the Translucency and Whiteness of Resin Composites

Abstract

This study evaluated the reliability of relative translucency parameter (RTP₀₀) and whiteness index (WI_D) measurements of single-shade and multi-shade resin composites (RCs) with different thicknesses using a spectrophotometer and a mobile colorimeter application. A total of 192 specimens were prepared from six RCs, including three single-shade and three multi-shade materials, with 1 mm and 2 mm thicknesses. Color measurements were performed at baseline and after 7 days using a spectrophotometer and a mobile colorimeter application. RTP₀₀ values were calculated using the CIEDE2000 formula, and WI_D values were calculated using the CIELAB-based formula. Reliability was assessed using intraclass correlation coefficients, and data were analyzed with robust ANOVA. Single-shade RCs showed higher RTP₀₀ and WI_D values than multi-shade RCs. ColorMeter values were higher than spectrophotometer values. Material and method effects were significant for ΔRTP₀₀ and ΔWI_D, with interactions. Reliability analysis showed higher consistency for the spectrophotometer. Mobile colorimeters provide practical and cost-effective measurements, while spectrophotometers remain a more reliable option for precise color assessment. Material type, thickness, and measurement method should be considered when evaluating optical properties for clinical use.