Surface changes of various bulk-fill resin-based composites after exposure to different food-simulating liquid and beverages.

OBJECTIVE: To evaluate surface roughness, hardness, and morphology changes of various bulk-fill resin composites eroded by different food-simulating liquids and beverages.

MATERIALS AND METHODS: One hundred and thirteen specimens were fabricated in polytetrafluoroethylene cylindrical mold (10 mm in diameter and 4 mm in thickness). Before immersion, baseline data of roughness, Vicker's microhardness were recorded and surface characteristics were examined using scanning electron microscopy (SEM). Each product of specimens (SDR, Dentsply; SonicFill, Kerr; Tetric N-Ceram Bulk Fill, Ivoclar Vivadent AG; and Filtek Bulk Fill, 3M ESPE) were divided into 5 groups for spicy and sour soup, spicy soup (Tom Yum), pineapple juice, passionfruit juice, and deionized water (served as a control). Specimens were then alternately immersed in storage agents for 5 seconds and artificial saliva for 5 seconds over 10 cycles. Specimens were stored in artificial saliva for 22 hours. This process was repeated for 28 days. After immersion, surface hardness and roughness of specimens were evaluated at 7, 14, 21, and 28 days and data were analyzed by two-way repeated ANOVA and Tukey's HSD (α = 0.05). Surface morphology of specimens was also examined on day 28.

RESULTS: The SDR group had the most statistically significant decrement in hardness (25.65 ± 1.74 kg/mm2 in mean difference) and increment in roughness (0.26 ± 0.10 μm in mean difference; P < .05). Passionfruit juice caused the most surface changes in bulk-fill resin composites. SEM photomicrographs showed surface changes of all resin composites in varying degrees.

CONCLUSION: Acidic food-simulating liquids and beverages significantly increased the surface roughness and decreased surface microhardness of bulk-fill resin composites after evaluation at the end of the 28-day immersion period.

CLINICAL SIGNIFICANCE: For restoration of the affected teeth in patients who consume acidic food and beverages, roughness and erosion of resin composites should be considered. All of bulk-fill resin-based composites except SDR may be suitable for restorations in these patients.