Influence of different finishing, aging with coffee, and repolishing protocols on the properties of nanoparticle composite resins

Considering the variability of finishing protocols for composite resins, the literature does not offer a consensus about the influence of these approaches to obtain a final polishing and whether the physical properties of these composite resins change at different analysis times. Therefore, the study analyzed the microhardness, roughness, color stability, and gloss of a nanocomposite resin with different finishing, aging with coffee, and repolishing protocols. Nanocomposite resin samples were divided into three finishing protocol groups: Diamond burs (F and FF), multi-fluted tungsten carbide burs (18 and 30 flutes), and coarse and medium abrasive discs (Soflex-3M). All protocols used spiral rubber tips (F and FF) for polishing. Knoop microhardness (KHN), roughness (Ra), color changes (ΔE00 and YI), and gloss (GU) were analyzed. Scanning electron microscopy provided images of resins and finishing and polishing instruments. Resin KHN (