Printing Parameters And Aging Impact 3D-Printed Flexible Denture Resins

This study explores the effect of build orientation, layer thickness, support structures, and thermocycling influence on surface roughness, water absorption, and color stability in 3D-printed flexible denture resin. Disc specimens (15×2 mm) were fabricated using 3D-printed denture base (Graphy Resin THD) and 3D-printed flexible denture resins (Graphy Resin TFDH and 3Dresyn OD FDB) and conventional PMMA (Huge Dental, Shadong). DLP 3D printing was performed with variations in build orientation (30°, 40°, 45°), layer thickness (50 µm, 100 µm), and support structure (partial, full). The specimens underwent water immersion and thermocycling (5000 cycles, to simulate 5 years of denture use). Surface roughness was measured with a profilometer, water absorption and color change (ΔE values) was quantified using a spectrophotometer before and after thermocycling. Data were analyzed using ANOVA with post hoc testing (p<0.05). Thermocycling increased surface roughness, particularly in samples with higher build orientations (45°) (p<0.05), but lesser effects in the flexible denture resin specimens. Water absorption increased after thermocycling, though differences were not statistically significant across groups (p<0.05). Color changes were most notable in samples with higher surface roughness, with the greatest color shifts observed in conventional PMMA (M= 1.459 ± 0.248) and 3Dresyn OD FDB (M= 1.38 ± 0.762) after thermocycling. Thermocycling and build orientation influence the surface roughness of 3D-printed flexible denture resins. Clinically, this may cause plaque buildup, discoloration, and reduced longevity, highlighting the importance of optimizing parameters for durability and aesthetic stability.