Color Stability of Different CAD/CAM Complete Denture Resins

The purpose of this in vitro study was to evaluate the color stability of resins for complete dentures produced with different technologies after immersion in coffee solution. 50 square-shaped specimens were prepared from different resins for complete dentures (n=10): Probase Hot (PH; Ivoclar AG), IvoBase CAD (IBC; Ivoclar AG), Ivotion Dent white (ID, Shade A2; Ivoclar AG), Dima Print Denture Base (DPDB; Kulzer), Dima Print Denture Teeth (DPDT, Shade A2; Kulzer). One side of each specimen was polished according to manufacturers' instructions (POL) while the other one was left unpolished. (UNPOL) (T0). The specimens were immersed in a coffee solution at 37 °C for 28 days (T28). During the storage period, the staining solution was replaced every 24 h. The CIELab color. differences (ΔEab) between the different time intervals were evaluated using a live-video. comparative spot digital colorimeter (Smart_Vision). Data were collected and statistically analyzed (p<0.05). The highest color stability was recorded for IBC UNPOL (∆E= 0.32; p<0.05). All specimens scored an acceptable ∆E, except for DPDT UNPOL (∆E= 4.56) which scored significantly lower as compared to all the other specimens (p>0.05). Milled and 3D printed resins for complete dentures demonstrated comparable color stability to traditionally-fabricated materials. Polishing influenced the color stability only in the 3D printed white resin where the unpolished group reached an clinically unacceptable level of color change after staining.