Color Stability of Different CAD/CAM Complete Denture Resins.

Purpose: 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.

Materials and methods: 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).

Results: 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).

Conclusions: 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.