Effects of Mouthwashes and Surface Treatments on the Color Stability and Surface Roughness of a Three-Dimensional Printed Interim Crown Material

Background: To evaluate the color stability and surface roughness of a 3D-printed interim crown material subjected to different surface treatments while immersed in various mouthwashes. Methods: The specimens (n=56) were manufactured with a digital light processing 3D printer. Half of the specimens were coated with one layer of Ultra Glaze varnish, and other half were polished with OptraGloss. After the initial color and surface roughness values were measured, specimens were immersed in different solutions [3 mouthwashes (Andorex, Tantum Verde and Listerine) and distilled water] for 24 hours. After solution exposures, color and surface roughness measurements were repeated, and the color change (ΔE) was calculated. Two-way ANOVA and Tukey’s test were performed to analyze the color difference and surface roughness of the specimens (p< .05). Results: Listerine caused lower discoloration compared with other mouthwashes in both polish (4.11±1.0) and glaze (3.71±0.98) groups (p< .05). ∆E was greater than the perceptibility (1.3) and acceptability thresholds (2.25) for both polish and glaze groups immersed in mouthwashes. Before solution immersion, the polish group (0.421±0.122) had greater surface roughness values than did glaze group (0.073±0.024) (p< .001). The surface roughness of the mouthwashes and distilled water were similar for both polish and glaze groups (p> .05). After solution immersion, all groups showed greater surface roughness, except for the polish group, which was immersed in Tantum Verde (p< .05). Conclusion: Mouthwashes negatively impacted the surface roughness and color stability of 3D-printed resin. The use of glazes for 3D-printed interim crowns can be recommended for long-term use. Keywords: Mouthwashes, Surface Properties, Temporary Dental Restoration, Tooth Discoloration