Effect of Common Staining Beverages on the Color Stability of Additively and Subtractively Manufactured Provisional Materials.

Background/

Objectives

The increasing use of digital manufacturing techniques in prosthodontics has raised concerns regarding the long-term esthetic performance of provisional restorations. This in vitro study aimed to compare the color stability of provisional restorations fabricated by additive (3D-printed) and subtractive (milled) manufacturing techniques after immersion in common staining beverages.

Methods

Eighty polymethyl methacrylate (PMMA)-based specimens (16 × 1 mm) were fabricated and divided into two groups: additive (n = 40) and subtractive (n = 40). Each group was immersed in coffee, red wine, green tea, or cola for 60 and 120 h at 37 °C. Color measurements were recorded using a spectrophotometer in the CIE LCh* system, and color differences (ΔE00) were calculated using the CIEDE2000 formula. Data were analyzed using repeated-measures analysis of variance (ANOVA) and Tukey post hoc tests (α = 0.05).

Results

Additively manufactured specimens showed significantly higher color change (ΔE00) values than subtractively milled specimens across all immersion media and time intervals (p < 0.05). Red wine and coffee caused the greatest discoloration, whereas cola produced the least effect.

Conclusions

Within the limitations of this study, additive manufacturing resulted in lower color stability than subtractive fabrication. Subtractive PMMA materials exhibited superior optical behavior, suggesting their suitability for long-term provisionalization in esthetically demanding clinical situations.