Airbrush vs. Brush-Applied Palaseal Glaze on 3D-Printed Apex Base Denture Resin: Surface, Optical, and Mechanical Properties Before and After Thermocycling

This in vitro pilot study evaluated airbrush and brush application of a denture glaze (Palaseal) on the flexural, surface, and optical properties of a 3D-printed denture base resin (Apex Base) using a DLP printer (Sprintray Pro 2), compared with polished and unpolished controls, before and after thermocycling (1000 cycles). Water sorption and solubility were measured at baseline, with ISO 20795-1:2013 values used as reference benchmarks. Flexural, surface, and optical outcomes were measured (n = 10 per group; n = 5 for sorption and solubility). Polished specimens showed the largest decline in flexural strength after thermocycling (67.3 to 49.3 MPa). Spray-glazed specimens showed no significant decline but had the lowest baseline values. Strength was below the 65 MPa reference value in 21 of 40 specimens at baseline and 31 of 40 after thermocycling, and modulus was below the 2000 MPa reference value in 79 of 80. Sorption and solubility were above the reference values in all groups, but specimen dimensions deviated from the standard, so these comparisons are descriptive. Glazing produced a measurable color difference from the unmodified resin. Airbrush and brush protocols did not differ significantly on any outcome. Findings apply to the glaze curing conditions tested.