Effect of staining solutions on color and translucency stability of resin-composite computer-aided design and computer-aided manufacturing blocks.

Background: The purpose of this study was to investigate the color difference (ΔE₀₀) and translucency changes (ΔTP₀₀) of resin-composite computer-aided design and computer-aided manufacturing blocks after exposure to staining solutions.

Methods: A total of 250 rectangular specimens (1.0-mm thick) were prepared from 4 resin-based composites (Brilliant Crios [Coltène Whaledent], Lava Ultimate [3M], Hyramic [Upcera], and Shofu HC [Shofu]) and a polymer-infiltrated ceramic network material (Vita Enamic [Vita Zahnfabrik]). These specimens were divided into 5 groups and stored in 5 solutions (artificial saliva, cola, black tea, coffee, red wine) at 37 °C for 3, 7, and 14 days to simulate approximately 3, 7, and 14 months, respectively, of clinical staining in the oral environment. Then, toothbrushing was conducted for 4 minutes every 24 hours of immersion to remove extrinsic staining. Measurements of color coordinates were taken at baseline and subsequent testing intervals, and changes in color and translucency were calculated.

Results: The results of the 3-way repeated-measures analysis of variance indicated that material, staining beverages, and time interval and the interactions between these factors collectively affected the alterations in both color and translucency (P < .001). At the 14-day immersion period, the ΔE₀₀ values of all tested materials varied from 0.43 to 2.12 and were clinically acceptable (ΔE₀₀ < 1.8), except for Lava Ultimate and Hyramic in red wine. All materials showed a decrease in translucency, with the ΔTP₀₀ values ranging from -0.23 through -1.34 over 14 days and were clinically acceptable (translucency acceptability threshold < 2.62).

Conclusions: Differences in color and translucency changes were observed between resin-based composites and polymer-infiltrated ceramic network material. All tested materials showed acceptable color and translucency changes when exposed to different staining solutions after the 14-day staining and toothbrushing simulation.

Practical implications: Discoloration of resin-matrix ceramics due to immersion in solution is related to material type and solutions but is generally acceptable. The dietary habits of the patient should be considered in material selection.