Objectives: To evaluate the influence of printing orientation on color and translucency of 3D printing restorative resins.
Methods: Four 3D printing resin systems in the available shades (DFT-Detax Freeprint Temp- A1, A2,A3; FP-Formlabs Permanent Crown- A2,A3,B1,C2; FT- Formlabs Temporary CB- A2,A3,B1,C2; GCT-GC Temporary- Light, Medium) were evaluated. Three samples (10×10×1.2 mm) from each material were printed at two different printing orientations (0° and 90°) and polished to 1.00 ± 0,01 mm of thickness. Spectral reflectance was measured against black background using a calibrated spectroradiometer, CIE D65 standard illuminant and the 45°/0°geometry. Color and translucency differences were evaluated using CIEDE2000 metric (ΔE00) and 50:50% perceptibility (PT00 and TPT00) and acceptability (AT00 and TAT00) thresholds.
Results: In general, color changes due to printing orientation at (0° and 90°) were mainly produced by ΔL* or ΔC* . ΔE00 were above PT00 for all DFT shades, FP-B1, FP-C2, FT-A2 and FT-B1. Only for DFT-1, ΔE00 was above AT00. ΔRTP00 values were above TPT00 for DFT-A1, DFT-A3, FP-B1 and FT-B1, but lower than TAT00. The direction of the changes in translucency (ΔRTP00) depends on the material and shade.
Significance: The selection of building orientation (0° and 90°) for the 3D printed resins influence the visual color and translucency and therefore their esthetic appearance. These aspects should be considered when printing dental restorations using the evaluated materials.
Keywords: 3D printing resin; Additive manufacturing; CIEDE2000 metric; Color; Printing angle; Provisional restoration; Translucency parameter.
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