This study evaluated the effects of thermocycling on surface roughness (Ra), gloss (GU), color stability (ΔE00), and water sorption of interim materials manufactured by three methods. Disc specimens (n = 20/group) were fabricated from a conventional bis-acryl (PreVISION® Temp), a computer-aided design/computer-aided manufacturing (CAD/CAM)-milled methacrylate-based composite (StructurCAD Disc®), and a 3D-printed resin composite (Alias Dental Temp C 5–55 °C). Nonparametric tests were used (α = 0.05). After thermocycling, Ra increased in the conventional and 3D-printed groups, whereas the milled group demonstrated a decrease (p < 0.05). GU decreased across all groups (p < 0.001) and differed among materials (p = 0.021), with a significant difference only between milled and 3D-printed groups. Color stability differed among materials (p < 0.001): the milled group showed the lowest ΔE00 perceptibility threshold (below PT00 = 0.81), whereas conventional and 3D-printed groups exceeded the acceptability threshold (AT00 = 1.81). Water sorption differed among groups (p < 0.001), with a significant difference between the milled and 3D-printed groups (p < 0.001). The tested 3D-printed material exhibited less favorable post-thermocycling optical properties, whereas the evaluated CAD/CAM-milled material demonstrated more favorable overall surface and optical performance under the applied aging conditions.
Bakkaloğlu et al. (Fri,) studied this question.