Effect of denture cleansers and surface treatments on the color stability, gloss, and wettability of CAD-CAM denture bases.

PURPOSE: To evaluate the impact of surface treatments and chemical denture cleansers on the surface color stability, gloss, and wettability of compression-molded, 3D-printed, and milled denture base materials.

MATERIALS AND

METHODS

Specimens (12 × 16 × 7 mm) were fabricated from a standardized STL file in three denture base materials (compression-molded, 3D-printed, and milled resins; n = 80 each) and assigned to polish-only or protective-coated (Optiglaze) subgroups. Specimens were immersed in one of four cleaning solutions: Polident (alkaline peroxide), Val-Clean (potassium caroate), Renew (alkaline hypochlorite), or distilled water (control group). Thirty immersion cycles per day were performed for 12 days, for a total of 360 cycles, simulating approximately 1 year of once‑daily denture cleaning. Color stability was evaluated using a spectrophotometer with the CIEDE2000 (ΔE00) formula. Surface gloss was measured with a gloss meter, and wettability was assessed by static contact angle using an optical tensiometer. Statistical analyses were conducted using three-way ANOVA. Color changes on acceptability and perceptibility were evaluated using one-sided, one-sample t-tests (thresholds of 1.8 and 0.8, α = 0.05).

RESULTS

Renew produced the highest mean ΔE00 (3.90 ± 0.33), exceeding distilled water (1.76 ± 0.33), Polident (0.92 ± 0.80), and Val-Clean (0.78 ± 0.56). Using the acceptability threshold (AT) of ΔE00 = 1.8, all Polident and Val-Clean groups remained acceptable for milled and 3D-printed materials. In contrast, compression-molded materials exhibited greater color instability. All Renew groups exceeded the AT regardless of surface treatment or fabrication method. Gloss change was also significant; Optiglaze combined with Val-Clean caused some of the largest gloss losses in 3D‑printed samples (-17.99 ± 9.82, p < 0.0001) and compression-molded samples (-13.13 ± 4.21, p < 0.0001). Polished surfaces generally lost less gloss, such as Polident-treated compression-molded resin (-5.92 ± 3.33, p = 0.0048). For wettability, Optiglaze increased hydrophobicity in 3D-printed specimens in distilled water (+6.33 ± 7.11°, p = 0.0033) but decreased it when combined with Renew in compression-molded resin (-18.54 ± 6.70°, p < 0.0001). Polident or Val-Clean on polished surfaces best preserved color, gloss, and wettability.

CONCLUSION

Renew produced the greatest overall changes in color and wettability. Gloss changes were strongly material‑ and treatment‑dependent. Optiglaze‑coated 3D‑printed and compression-molded bases immersed in Val-Clean showed pronounced gloss loss. Polished surfaces generally retained gloss better. Compression-molded materials were more susceptible to color change than milled or 3D-printed materials, and the Optiglaze did not consistently reduce changes in color, gloss, or wettability. These findings may inform future research and the development of evidence-based denture-cleaning protocols; however, clinical studies are needed before specific recommendations can be made.