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    Surface roughness and color stability of 3D-Printed denture base materials after simulated brushing and thermocycling
    (MDPI, 2022) Çakmak, Gülce; Molinero Mourelle, Pedro; De Paula, Marcella Silva; Akay, Canan; Cuellar, Alfonso Rodriguez; Dönmez, Mustafa Borga; Yılmaz, Burak
    Three-dimensional (3D) printing is increasingly used to fabricate denture base materials. However, information on the effect of simulated brushing and thermocycling on the surface roughness and color stability of 3D-printed denture base materials is lacking. The aim of this study was to evaluate the effect of brushing and thermocycling on the surface roughness and color stability of 3D-printed denture base materials and to compare with those of milled and heat-polymerized denture base resins. Disk-shaped specimens (Ø 10 mm × 2 mm) were prepared from 4 different denture base resins (NextDent Denture 3D+ (ND); Denturetec (SC); Polident d.o.o (PD); Promolux (CNV)) (n = 10). Surface roughness (Ra) values were measured before and after polishing with a profilometer. Initial color coordinates were measured by using a spectrophotometer after polishing. Specimens were then consecutively subjected to simulated brushing (10,000 cycles), thermocycling (10,000 cycles), and brushing (10,000 cycles) again. Ra and color coordinates were measured after each interval. Color differences (?E00) between each interval were calculated and these values were further evaluated considering previously reported perceptibility (1.72 units) and acceptability (4.08 units) thresholds. Data were analyzed with Friedman, Kruskal–Wallis, and Mann–Whitney U tests (? = 0.05). Ra (p ? 0.051) and ?E00 (p ? 0.061) values among different time intervals within each material were similar. Within each time interval, significant differences in Ra (p ? 0.002) and ?E00 values (p ? 0.001) were observed among materials. Polishing, brushing, and thermocycling resulted in acceptable surface roughness for all materials that were either similar to or below 0.2 µm. Color of ND printed resin was affected by brushing and thermocycling. All materials had acceptable color stability when reported thresholds are considered.
  • Küçük Resim
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    Surface roughness and stainability of new-generation denture base materials after brushing and coffee thermocycling
    (SPRINGER HEIDELBERG, 2022) Çakmak, Gülce; Dönmez, Mustafa Borga; De Paula, Marcella Silva; Akay, Canan; Chavan, Amit; Schimmel, Martin; Yılmaz, Burak
    Disk-shaped specimens were prepared from additively (NX and DT), subtractively (MZ), and conventionally manufactured denture base resins (CV). Surface roughness and color coordinates were measured after polishing, simulated brushing, and coffee thermocycling, while surface roughness was also measured before polishing. Polishing reduced the surface roughness of all materials. Brushing and coffee thermocycling increased the surface roughness of only DT. CV had the highest susceptibility to consecutive brushing and coffee thermocycling as it had the highest surface roughness, which was above the clinically acceptable threshold. All materials had similar stainability; only MZ had perceptible color change after brushing. Even though stainability of tested denture base resins was similar, additively or subtractively manufactured computer-aided design and computer-aided manufacturing (CAD-CAM) resins had smoother surfaces after brushing and coffee thermocycling, regardless of the material. Therefore, complete dentures made out of these CAD-CAM resins may have favorable surface properties in the long term.