Comparison between nanohybrid filler and submicron composite resin shade on color changes after polymerization

Background: Initial color determination of composite resins before polymerization is crucial to achieve an esthetic result that mimics the original tooth color. A filler particle size and composition affect the color change of the composite resin after polymerization despite the improvement in the chemical composition and filler of the composite resin. Objective: The effects of nanohybrid filler and submicron composite resin shade on color changes after polymerization were determined. Methods: Disc-shaped composite resin samples (diameter and thickness of 12 mm and 2 mm, respectively) were categorized into six groups, with each group containing 10 plates, according to the shade and type of filler (nanohybrid UD1, UD2, UD3; submicron OA1, OA2, OA3). Digital photographs were taken before and after polymerization. The changes in color (ΔEFNx01ab values) were determined using software via eLABor_aid. Result: Only the Micerium EHRi UD1 composite resin group exhibited ΔEFNx01ab < 3.3. The independent t-test revealed significant differences in the ΔEFNx01ab (P < 0.05) between the nanohybrid and submicron composite resins in all shade groups (A1, A2, and A3). One-way analysis of variance revealed significant differences in ΔEFNx01ab (P < 0.05) among A1, A2, and A3 between the nanohybrid and submicron composite resin groups. Tukey’s post hoc test revealed significant differences in ΔEFNx01ab (P < 0.05) for the Micerium EHRi UD1 group compared with those of the UD2 and UD3 groups, as well as in the case of the Tokuyama Palfique OA1 group compared with those of the OA2 and OA3 groups. Conclusion: Nanohybrid filler and submicron composite resin shade affected color changes after polymerization. Compared to the darker color groups, brighter shades (UD1 and OA1) exhibited a lower-intensity color change.