Evaluation of Color Stability of Experimental Dental Composite Resins Prepared from Bis-EFMA, A Novel Monomer System

Color stabilities of experimental composite resins based on Bis-EFMA (a novel bisphenol A [BPA]-free monomer system) with 3M ESPE FiltekTM Z250 (FZ) and experimental composite resins based on bisphenol A-glycidyl methacrylate (Bis-GMA) and urethane dimethacrylate (UDMA) were compared. Bis-EFMA was synthesized via the reaction between 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene and 2-(methacryloyloxy)ethyl isocyanate. Experimental Bis-EFMA-, Bis-GMA-, and UMDA-based composites were prepared (20% of each of Bis-EFMA, Bis-GMA, UDMA, or triethylene glycol dimethacrylate (TEGDMA) and 60% glass filler). Eighty composite resin materials were produced (n=5). The initial color values of composites on the first day, first week, and after the first month after immersion into black tea, coffee, cola, and water solutions were measured using a spectrophotometer (VITA Easyshade (R) V; Zahnfabrik, Bad Sackingen, Germany) against a white background. UDMA- and Bis-EFMA-based composite resins exhibited significantly less Delta E and Delta L compared to Bis-GMA based composite resins (p < 0.05). No significant difference was found between FZ and other composites (p > 0.05). Tea and coffee caused significant changes in total color, light value, red-green, and blue-green coordinate values changes (Delta E, Delta L, Delta a, and Delta b, respectively) compared to water and cola (p < 0.05). At one month compared to one week and one day, Delta E, Delta L, Delta a, and Delta b were significantly different (p < 0.05). Bis-EFMA has the potential to be used in commercial dental composites as a substitute for Bis-GMA in terms of better color stability.