Color Stability of PMMA Resins for Complete Dentures Produced with CAD/CAM and 3D-Printing Technologies: An In Vitro Study.

The article focuses on evaluating the color stability of polymethyl methacrylate (PMMA) resins used for complete dentures fabricated via conventional and digital technologies, including milling and 3D printing. Sixty resin specimens from six different materials were immersed in a coffee staining solution for 28 days, and color changes (ΔE) were measured using two spectrophotometers, VITA Easyshade and SpectroShade. Results showed that all materials experienced some color change, but resins produced with digital milling techniques demonstrated significantly higher color stability compared to conventional heat-cured and 3D-printed resins. Scanning electron microscopy revealed no significant surface morphology changes after staining immersion. The study concludes that digital workflows, particularly milling, yield denture resins with better color stability when exposed to common staining agents like coffee.