The influence of printing angle on color and translucency of 3D printed resins for dental restorations.

Abstract

To evaluate the influence of printing orientation on color and translucency of 3D printing restorative resins. 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±0,01mm 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. 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. 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.