The New Era of Provisional Restorative Materials: Surface Roughness Responses to Artificial Aging

Provisional restorative materials can be fabricated using conventional, subtractive, and additive manufacturing techniques; however, evidence regarding the combined effects of artificial aging and beverage exposure on the surface characteristics of these materials remains limited. This study evaluated the influence of material type, storage medium, and artificial aging on the surface roughness of provisional restorative materials fabricated using different manufacturing workflows. Ninety square-shaped specimens (15 mm × 15 mm × 1.5 mm; n = 10 per experimental group) were prepared from a conventional polymethyl methacrylate resin (Unifast III), a CAD/CAM material (VITA CADTemp), and a three-dimensional (3D)-printed resin (NextDent C&B MFH). All specimens were standardized using a sequential silicon carbide finishing and polishing protocol before testing. Specimens were stored in distilled water, coffee, or Coca-Cola and assessed at baseline (T0), after 15,000 thermocycles and 7 days of immersion (T1), and after 30,000 thermocycles and 14 days of immersion (T2). Surface roughness (Ra) was measured using a non-contact 3D optical profilometer. A significant interaction among material type, storage medium, and aging period was observed (p = 0.017). VITA CADTemp consistently exhibited the lowest surface roughness values (0.158–0.215 µm), followed by NextDent C&B MFH (0.245–0.382 µm) and Unifast III (0.337–0.617 µm), with significant differences among all materials at each evaluation period (p < 0.05). At T2, significant increases in surface roughness were observed in Unifast III specimens stored in coffee and Coca-Cola and in NextDent C&B MFH specimens stored in coffee (p < 0.05), whereas no significant changes were detected in VITA CADTemp or distilled-water groups. Within the limitations of this study, surface roughness depended on material, storage medium, and cumulative aging, with VITA CADTemp exhibiting the lowest values. Mean Ra exceeded the commonly cited 0.2 µm threshold for plaque retention in Unifast III and NextDent C&B MFH at all measurement points, and in VITA CADTemp only after coffee exposure at T2.