Effect of aging on color and whiteness of single shade and group shade resin composites in restorations with different cavity configurations

Abstract

Objectives: To evaluate the effect of aging on the color and whiteness of single- and group- shade resin composites in restorations with different cavity configurations and dental shades. Methods: Class I and V cavities (length of 8.0 mm, depth of 2.0 mm and width of 2.5 mm) were prepared in artificial acrylic mandibular right molars with different shades (A1, A2, A3, A3.5, and A4). Three single- (OMNI- Omnichroma, UNI- Vittra APS Unique, CHA- Charisma Diamond ONE) and two group-shade (FIL- Filtek Uni versal Restorative, HAR- Harmonize) resin composites were evaluated. The ISO 4892–2 was used to perform the accelerated artificial aging (AAA). Spectral reflectance measurements were obtained and CIELAB color co ordinates were calculated (CIE D65 standard illuminant and 2º CIE1931 Standard Observer) at baseline and after AAA. CIEDE2000 color differences (ΔE00), %ΔL00, %ΔC00, %ΔH00 and whiteness variations (ΔWID) were calculated. Generalized linear models (GLM) were used for the comparison between combined groups (shade, aging, and cavity configuration) for each outcome individually and all possible associations between groups (α = 0.001). The corresponding perceptibility (PT00 =0.8 and WPT =0.7) and acceptability (AT00 =1.8 and WAT = 2.6) thresholds were used for the analysis of the results. Results: In general, the color stability of single- and group-shade composites after aging was better for Class V restorations, presenting lower ΔE00 and ΔWID values. For Class I restorations, group shade composites (FIL and HAR) exhibited lower ΔE00 and ΔWID values; FIL generally showed the lowest ΔE00 and ΔWID values for both Class I and Class V restorations. These values were below the AT00 and WAT values for Class V restorations, but above the AT00 and WAT values for Class I restorations. Clinical significance: The influence of cavity configuration on color and whiteness stability indicates that resto ration geometry should be considered when predicting long-term shade matching and esthetic durability of single- and group-shade composites.”