Comparative analysis of surface characteristics and color stability in zirconia-reinforced resin composites: 3D printing, subtractive, and layering techniques
Luiza Freitas Brum Souza1, Kétlin Fagundes Teixeira2, Ana Carolina Cadore-Rodrigues3
1Postdoctoral student, Clinic for Masticatory Disorders and Dental Biomaterials, Center for Dental Medicine, University of Zurich, Zurich, Switzerland.
Statement Of Problem:
Despite growing interest in zirconia-reinforced resin composites, the influence of manufacturing techniques on their surface and optical stability remains unclear.
Purpose:
The purpose of this in vitro study was to evaluate the surface characteristics and color stability of zirconia-reinforced resin composite materials produced via 3 techniques: 3-dimensional (3D) printing, subtractive manufacturing, and layering.
Material And Methods:
Thirty-six disks (Ø10×1.0 mm) were prepared and divided into 3 groups: 3D printing (PriZma 3D Bio Crown; MakertechLabs), subtractive manufacturing (Lava Ultimate; 3M), and layering (Filtek Z350 XT; 3M). Surface properties were assessed using roughness analysis and scanning electron microscopy (SEM). Color coordinates (L*, a*, b*) were recorded using a spectrophotometer (SP60; X-Rite) at baseline, after staining (coffee or red wine for 12 days), and after repolishing (Superfix Dental Finishing & Polishing Disc System; TDV). Statistical analysis included color differences (∆E00) and translucency parameter differences (∆TP00), considering acceptability (AT) and perceptibility thresholds (PT) (α=.05).
Results:
Three-dimensional printing exhibited higher Ra than subtractive (P<.001) or layering (P=.010). For Rz, 3D printing and Layering were similar and better than Subtractive (P<.001). SEM revealed porous surfaces in 3D printing, contrasting with denser surfaces in Subtractive and Layering. All groups showed color changes exceeding AT, with 3D printing significantly higher after coffee or red wine exposure (P<.05). Repolishing reduced the ∆E00 of Subtractive below PT after coffee staining and below AT after wine staining. ∆TP00 altered after coffee staining, with Subtractive below AT after wine staining. Repolishing reversed ∆TP00 below AT for all conditions.
Conclusions:
Three-dimensional printing and layering resulted in higher surface roughness, greater color changes, and lower translucency than the subtractive technique.
