Whitening Toothpaste Alone or with a Home-Use or Professional Polishing Paste on a Stained Composite In Vitro

Whitening toothpastes are widely used by patients with composite restorations, and polishing pastes are increasingly applied to the same surfaces. Forty nanohybrid composite discs (8 × 2 mm) were polished, allocated to four groups (n = 10) and stained in coffee for 144 h at 37 °C. Brushing representing an assumed one month of use was performed with a powered toothbrush (4 min); combined protocols added a second product (home-use paste 64 s, prophylaxis paste 12 s). Surface roughness (Ra) and CIELAB coordinates were recorded at baseline (T0), after staining (T1) and after brushing (T2). Because the intervention occurred only between T1 and T2, ΔRa was the primary roughness outcome; colour recovery (ΔE00, T0 → T2) and net whiteness change (ΔWID) were the primary colour outcomes. On ΔRa, the prophylaxis paste alone roughened the surface relative to the control (p = 0.005) and alone left specimens whiter than baseline; its mean post-brushing Ra reached the 0.2 µm plaque-retention threshold, the confidence interval including that value. Adding the home-use paste changed neither roughening nor net whiteness but left a larger residual colour difference than the toothpaste alone. Whiteness gain and residual mismatch favoured different arms, and the arm that whitened also roughened.