Color stability of conventional and bulk fill composite resins

ABSTRACT Objective: This study compared the color stability of different dental composite resins after prolonged exposure to a coffee solution. Methods: Sixty-four cylindrical discs (10 mm diameter x 2 mm thickness) were prepared using 8 different dental composite resins (n=8, per group). The specimens were first immersed in artificial saliva for 24 h followed by immersion in a coffee solution for 14 days. The assessment of chromatic variation (ΔE) was performed with the aid of a Vita Easyshade Advanced spectrophotometer (VITA Zahnfabrik, Bad Sackingen, Germany). The color of each specimen was calculated based on the L*, a* and b* coordinates of the CIELab system. Results: Grandio SO had the lowest average chromatic variation (ΔE=7.77) after immersion in coffee solution. Durafill VS, Grandio and Z350 XT (ΔE=8.58; ΔE=9.52; ΔE=10.39, respectively) showed similar chromatic variation, with no statistical difference in relation to Grandio SO. However, the other dental composite resins evaluated showed statistically higher values of ΔE compared to Grandio SO, and Enamel HRi (ΔE=20.56) demonstrated the highest chromatic variation. Conclusion: The Bulk Fill and hybrid composite resins from the same manufacturer (Micerium, Avegno, Italy) showed greater chromatic variation than the other composite resins tested. Grandio SO (Voco, Cuxaven, Germany) had the lowest ΔE variation.

摘要 目的：本研究对比了不同牙科复合树脂在长时间浸泡于咖啡溶液后的色彩稳定性。方法：本研究使用8种不同的牙科复合树脂（每组n=8）制备了64个圆柱形试件（直径10 mm×厚度2 mm）。首先将试件置于人工唾液中浸泡24小时，随后转移至咖啡溶液中浸泡14天。采用Vita Easyshade Advanced分光光度计（VITA Zahnfabrik，巴德扎根芬，德国）对色彩变化量（ΔE）进行评估。每个试件的色彩基于CIELab系统的L*、a*、b*坐标进行计算。结果：经咖啡溶液浸泡后，Grandio SO的平均色彩变化量（ΔE=7.77）最低。Durafill VS、Grandio与Z350 XT的ΔE值分别为8.58、9.52、10.39，三者色彩变化程度相近，与Grandio SO无统计学差异。然而，其余受试牙科复合树脂的ΔE值均显著高于Grandio SO，其中Enamel HRi（ΔE=20.56）的色彩变化程度最高。结论：来自同一制造商（Micerium，意大利阿韦尼奥）的大块充填型（Bulk Fill）与混合型复合树脂，其色彩变化程度高于其余受试复合树脂。Grandio SO（Voco，德国库克斯哈芬）的ΔE变化量最低。