Objectives: The aim of this study was to evaluate the color stability, water sorption and solubility of recent bulk-fill restorative materials.
Materials and Methods Seventy disc shaped specimens (height:1mm, diameter:15mm) were prepared with a micro-hybrid composite resin (Z250; Filtek Z250, 3M ESPE), two resin-based bulk-fill (Filtek One Bulk Fill, 3M ESPE and EBF; Estelite Bulk-Fill Flow, Tokuyama Dental), glass ionomer-based restorative (Equia FF; Equia Forte Fil, GC Dental), self-cure and light-cure alkasite (CN; Cention N, Ivoclar Vivadent) and indirect composite resin (Gradia P; Gradia Plus, GC Dental) (n=10). Baseline color measurements were performed and mass of the samples (m1) were noted. Color measurements were repeated after 24 h and 28 days immersion of the specimens in water. After the 28-days immersion, mass was noted as m2. Specimens were kept in desiccators and final mass (m3) were recorded. The color change (ΔE00) water absorption (WSP) and water solubility (WSL) of the specimens were calculated. Results: After 28-days immersion, Gradia P showed significantly lower water sorption than EBF and Equia FF groups (p<0.05). Light-cured and self-cured CN groups showed similar sorption with resin composite groups (p>0.05). The lowest solubility was observed in Z250and Gradia P. The lowest (ΔE00) was observed in self-cured CN group (p<0.05) and Gradia P showed the highest ΔE00.

Conclusions: Light-cured and self-cured CN groups demonstrated similar sorption to the conventional composite resin and indirect composite resin. Self-cured CN demonstrated higher water solubility than composite resins. Restorative materials showed moderately unacceptable color change after 28-day immersion in distilled water. Keywords: Water Sorption, Solubility, Color Change.