Effect of Bevel Preparation on Color Adjustment Potential of One-Shade Composites

Aim: This study aimed to evaluate the effect of bevel preparation on the color adjustment potential (CAP) of three universal oneshade and one conventional resin composite used in anterior restorations. Materials and Methods: Three universal one-shade (Omnichroma, Vitra APS Unique, Charisma Topaz One and one conventional resin composite (Estellite Sigma Quick) were tested. Standardized cavities (6 mm diameter, 2 mm depth) were prepared in A2-shade acrylic molds, either without bevel or with a 2 mm, 45° bevel. Each group consisted of ten specimens (n=10). Restorations were placed in a single increment, lightcured, polished, and stored in distilled water for 24 hours. Color parameters (L*, a*, b*) were measured using a spectrophotometer (VITA Easyshade V), and ΔE values were calculated with the CIEDE2000 formula. The color adjustment potential index (CAP-I) was determined as CAP-I = 1 – (ΔEDUAL/ΔESINGLE). Data were analyzed using the t- test, ANOVA and Tamhane post hoc tests (α=0.05). Results: CAP-I values ranged from 0.57 to 0.86 in non-beveled and 0.85 to 0.94 in beveled groups. No statistically significant differences were found between bevel and and non-bevel designs except Omnichroma group (p=0.003). Omnichroma showed the lowest CAP in non-beveled groups (p