This laboratory study aimed to investigate the effects of toothbrushing with different toothpaste formulations on the color stability and surface roughness of CAD/CAM restorative materials following coffee-staining thermocycling. A total of 160 specimens were prepared from four restorative materials: IPS e.max CAD, CEREC Tessera, Shofu Block HC, and VITA Enamic (n = 40 each). Following initial measurements, specimens underwent thermocycling in a coffee solution (5000 cycles) to simulate staining. Each group was subsequently divided and brushed with either a whitening toothpaste containing hydrated silica and hydrogen peroxide or a non-whitening toothpaste containing hydrated silica only. A total of 10,000 brushing cycles were performed under standardized conditions. Color stability was assessed using ΔE₀₀ values, and surface roughness was quantified using the Ra parameter at baseline, after thermocycling, and after brushing. Data were analyzed using Kruskal–Wallis and Mann–Whitney U tests with the significance threshold set at p 0.05). Ra changes were also concluded by SEM. The performance of restorative materials under staining and mechanical aging stressors is material-dependent. Glass-ceramics displayed superior color stability after coffee exposure and greater resistance to brushing-related surface degradation, whereas resin-containing materials were more vulnerable. The choice of toothpaste formulation did not significantly affect color stability or surface characteristics, suggesting that intrinsic material properties play a more critical role in long-term esthetic outcomes. Selection of restorative materials plays a decisive role in ensuring the long-term esthetic success of dental restorations. Since intrinsic material properties strongly influence color stability and resistance to surface degradation, clinicians should carefully consider material choice during treatment planning to achieve durable and predictable outcomes.
Yanik et al. (Mon,) studied this question.