Effects of staining and artificial aging on optical properties of gingiva-colored resin-based restorative materials.

Objectives: To evaluate CIEDE2000/CIELAB differences in color (ΔE/ΔE), and translucency parameter (ΔTP/ΔTP), and gloss of gingiva-colored resin-based restorative materials upon staining/aging.

Materials And Methods: Disc-shaped, 10 mm in diameter, and 2-mm-thick samples (n = 5/group) were made from giomer (Beautifil II gingiva), oligomer-based (crea.lign GUM gel), CAD/CAM polymethyl-methacrylate-based (IvoBase CAD), PMMA-based (ProBase Hot), and dimethacrylate-based (SR Nexco Paste Gingiva). Color and gloss were recording using a benchtop spectrophotometer and gloss meter, respectively, at baseline (T0), and upon staining in coffee or red wine for 60 (T1) and 120 h (T2), or artificial aging of 150 kJ/m (T1) and 300 kJ/m (T2). Three-way analysis of variance (materials x staining conditions x time intervals), Tukey's test (α = 0.05), and Pearson's correlation test were used in analytical statistics.

Results: CIEDE2000 color differences ranged from 1.0 to 4.4 (coffee), 1.5 to 5.3 (wine), and 0.9 to 2.0 after artificial aging, with ΔE values being significantly higher for Beautifil than other materials (p < 0.05). ΔTP values ranged from 0.2 to 0.7 and were statistically higher upon staining in wine compared to artificial aging (p < 0.05). Gloss values at T0 were 76.7-87.0. Beautifil exhibited the lowest gloss retention (50.8-60.2%) after staining, compared to > 90% of other materials (p < 0.05). ΔE/ΔE and ΔTP/ΔTP were positively correlated (p < 0.0001).

Conclusions: Color, translucency, and gloss changes of gingiva-colored restorative materials were material- and staining/aging-dependent. Generally, wine caused greatest changes in color (with IvoBase CAD being the most color stable) and translucency parameter. All materials except Beautifil gingiva II exhibited staining- and aging-dependent gloss retention greater than 90% for all compared time intervals.

Clinical Relevance: Optical properties of resin-based gingiva-colored restorative materials depend on material, staining/aging conditions, and exposure time. Certain materials should be avoided in individuals with high consumption of red wine and coffee.