Effect of aging and fiber‐reinforcement on color stability, translucency, and microhardness of single‐shade resin composites versus multi‐shade resin composite.

Objective: The purpose of this study was to evaluate the effect of aging and fiber‐reinforcement on the color stability, translucency, and microhardness of single‐shade resin composites versus multi‐shade resin composite. Materials and Methods: Four resin composites (Filtek Z250, Omnichroma, Vittra APS Unique, Zenchroma) were tested. Three subgroups of specimens were prepared for each of the composites: control, polyethylene fiber‐reinforcement, and glass fiber‐reinforcement‐ groups (n = 10/per group). The samples were subjected to aging for 10,000 thermal cycles. Color differences (ΔE00) were calculated after aging. Relative translucency parameter (RTP00) and microhardness values were calculated before and after aging. A two‐way analysis of variance and the generalized linear model was used (p < 0.05). Results: The lowest and highest ΔE00 values were found for Filtek Z250 (0.6 ± 0.2) and Omnichroma resin composites (1.6 ± 0.4), respectively. The ΔE00 value of the polyethylene fiber‐reinforcement group (1.2 ± 0.6) was significantly higher than the ΔE00 value of the glass fiber‐reinforcement group (1.0 ± 0.4, p < 0.001). The RTP00 value of the glass fiber‐reinforcement group (1.92 ± 0.78) was significantly higher than the RTP00 value of the polyethylene fiber‐reinforcement group (1.72 ± 0.77, p < 0.001). The highest microhardness values were found in glass fiber‐reinforcement group (76.48 ± 17.07, p < 0.001). Conclusion: Single‐shade resin composites were more translucent, had higher color change, and lower hardness than multi‐shade resin composite. For relative translucency and microhardness, statistical significance was found in the material and fiber type interaction. The glass fiber‐reinforcement provided higher translucency, lower color change and higher microhardness values than polyethylene fiber‐reinforcement group after aging. Thermocycling had a significant impact on the color stability, translucency parameter, and microhardness of the tested resin composite materials. Clinical Significance: Single‐shade resin composite materials have greater color‐changing potential. The glass fiber‐reinforcement optimize resin material mechanical properties and color stability more than polyethylene fiber‐reinforcement. [ABSTRACT FROM AUTHOR]