This research aimed to investigate how surface finishing techniques impact the color stability, gloss, roughness, and wettability of monolithic polychromatic MJT 3D-printed denture resins. A total of 21 color variants of the same denture resin (TrueDent; Stratasys, Eden, MN, USA) were processed under two surface protocols—either polishing alone or polishing followed by glazing—yielding 42 groups and 420 specimens (n = 10 per group). Fabrication was performed using a PolyJet MJT 3D printer (J5 DentaJet; Stratasys, Eden, MN, USA). Color measurements were captured with a digital spectrophotometer before and after surface treatments, and ΔE00 and ΔC* values were computed according to the CIE2000 system. For tooth shades, comparisons were made against the 50%:50% perceptibility threshold (PT) of 0.8 and the acceptability threshold (AT) of 1.8, whereas gingival (pink) shades used PT = 1.72 and AT = 4.08. Surface gloss was quantified with a glossmeter, roughness via optical profilometry, and wettability by measuring contact angles using an optical tensiometer. Statistical significance of color changes was assessed using one-sided, one-sample t-tests against AT and PT, while t-tests evaluated the effect of surface treatment on gloss, roughness, contact angle, and ΔC* for each variant. Pairwise comparisons employed Fisher’s Protected Least Significant Differences (α = 0.05). In most instances, glazing induced ΔE00 changes exceeding PT and AT, although a few exceptions were noted. Glazed specimens generally displayed higher chroma and more vivid colors than polished-only samples. Gloss values were significantly elevated in glazed specimens (p < 0.0001), as was surface roughness (p < 0.0001 for most). In contrast, polished samples demonstrated higher contact angles (p < 0.0001 for most). Surface finishing markedly affects color, gloss, roughness, and wettability of MJT 3D-printed dentures. Glazing enhanced color saturation and gloss and produced more hydrophilic surfaces, but also increased roughness. These outcomes emphasize the critical role of surface treatment choice in achieving optimal clinical performance of MJT-fabricated dentures.
